Shoshannim

Boyd’s Bible Dictionary:

(lilies). Variously construed as a melody, bridal-song, and musical instrument (Psa. 45; 69; 80 titles). In the latter, eduth, “testimony,” is added.

Concise Bible Dictionary:

A word in the headings of Psalm 45 and Psalm 69, and of Psalm 80 with the word EDUTH, “a testimony,” added. The first Hebrew word signifies “lilies.” Gesenius refers it to the form of the instruments as resembling lilies. Fürst, as the name of one of the musical choirs. The LXX has “for alternate [strains].” In the heading of Psalm 60 is a similar word: SHUSHAN-EDUTH, “the lily of testimony.”
 
Aijeleth-Shahar
The hind of the morning
 
Alamoth
Virginals
 
Al-Taschith
Destroy not
 
Degree
To go up — ascend
 
Gittith
The wine-vat
 
Higgaion
Meditation
 
Jonah-Elem-Rechokim
The dove dumb (among) strangers
 
Mahalath
Disease
 
Mahalath Leannoth
Bitter disease
 
Maschil
To instruct
 
Michtam
Golden (psalm)
 
Muth-Labben
 
 
Neginah
A stringed instrument
 
Neginoth
The stringed instruments
 
Nehiloth
The pipes
 
Selah
Pause
 
Sheminith
Eight-stringed instrument
 
Shiggaion
Wandering ode
 
Shoshannim
The lilies
 
Shushan
The lily
 
Eduth
—  —  — of the Testimony

Bible Handbook:

The following valuable paper is part of an article from The Present Testimony, Vol. 1, and which appeared many years ago. We trust this public acknowledgment of the source from whence it is taken will be accepted by the publishers and proprietor of The Testimony: — 
1. Aijeleth-Shahar. Psalm 22 Title.
Aijeleth occurs only here and in Proverbs 5:19, “the loving hind”; and Jeremiah 14:5, “the hind. But there are many kindred words which confirm this meaning.
Shahar occurs about twenty-three times; it means morning, e.g. “when the morning arose” Genesis 19:15; “the breaking of the day” 32:24; and “the day breaketh,” 32:26 etc.
The marginal reading for Aijeleth-Shahar, given by the translators is, “hind of the morning.”
Query? Was this the name of an instrument; or of a tune to which the Psalm was to be sung; or was it rather a name given to the Psalm on account of its subject?
2. Alamoth occurs in 1 Chronicles 15:20, “with psalteries on Alamoth”; Psalm 46 title, “A song upon Alamoth.
The same word Alamoth (which is only the plural of the word commonly used for Virgin, as Isaiah 7:14, “a virgin shall conceive,”), is, however, found, Psalm 68:25, “the damsels playing,” Song of Solomon 1:3, “The virgins love thee”; Song of Solomon 6:8, “Virgins without number.”
“For the Virgins” (i.e. virgin voices) makes good sense, and accords with modern singing: as we say, “for boys’ voices.” It may, however, be the name of an instrument, or of a tune.
3. Al-taschith occurs in the titles of Psalms 57, 58, 59, and 75.
Al means not, and Taschith, destroy, as the translator’s margin reads “Destroy not.”
Observation must decide whether this was connected with the subject of the Psalms, or whether it was the name of a tune.
4. Degrees. Though Anglicized songs of Degrees in Psalms 120-134, a few words may not be amiss, inasmuch as “Degrees” is nearly as unintelligible to some as would Mangaloth be.
The same word is used for the steps of an altar (Exodus 20:26), steps of a throne (1 Kings 10:19); the stairs (2 Kings 9:13); the degrees of a sun-dial (2 Kings 20:9); a man of high degree (1 Chronicles 17:17); for a journey, “began to go up” (Ezra 7:9); the things which come into your mind (Ezekiel 11:5); he that buildeth his stories in the heaven (marg. ascensions or spheres) (Amos 9:6). The word from which it is derived means, simply, to go up — ascend.
Luther renders it, “in the higher choir,” higher, either as to position in which placed, or, perhaps, tone of voice.
Some have supposed these songs were sung on the steps of the temple: so the LXX, and Vulgate.
To my own mind, there is an eternal evidence in them, of their being written, in grace, for the times when, thrice in the year, the males were to go up from their homes and appear before the Lord. A few of them may also have reference to such goings up as Ezra’s from captivity.
5. Gittith. Psalms 8, 81, and 84.
The word Gath, winepress, is by most connected with this word, as the inhabitants of Gath were called Gittites.
Whether the vat; or Gath, the town, or an instrument of the name; or a tune is referred to; Query?
Someone suggests that they are all joyous songs, suited to be sung on such an occasion as a harvest-home, or a vintage.
6. Higgaion. Thus once rendered in Psalm 9:16. It occurs in three other places: — ”and the meditation of my heart” (Psa. 19:14); “harp with a solemn-sound (Psa. 92:3); “and their device against me” (Lam. 3:62).
The humming sound of a harp struck, is supposed to correspond to the indistinct thoughts of musing; or the device against one who is hated; for the device, in this case, tells, but indistinctly the hatred within.
I do not see why meditation, or solemn-sound or device might not have been put for Higgaion, and the verse anglicized with the addition of some words in italics, as (this was their) meditation, or device, or a solemn-sound, (this).
7. Jonath-Elem-Rechokim is only found in the title of Psalm 56.
Jonah means dove, as in Genesis 8:8,9,10,11,12; or pigeon, as in Leviticus 1:14.
Elem means bound; the verb is frequently used to mark silence; as, I was dumb (Psa. 39:3,10): but it is applicable to any binding: as Genesis 37:7, binding sheaves.
The word Elem only occurs here, where it is commonly said to mean silence, and in Psalm 58:1, where it is rendered “Do ye indeed speak righteousness, O congregation?” (i.e. mass of persons bound together).
Rechokim, in Hebrew, is a distinct word from Elem; though in English, sometimes printed as one with it. It is a participle of the verb translated “Be not far from me” (Psa. 22:11); see also Psalms 22:19; 35:22; 38:21; 71:12; 109:17; etc.
“The dove of silence (among) strangers” is a common literal translation.
The dove of — that which is bound — persons afar off — are its three representative terms in English. —  Compare the Psalm itself.
8. Leannoth. See Mahalath.
9. Mahalath occurs alone Psalm 53.
The dictionary says, “meaning uncertain.” Why not, as others, sickness, or disease taking it as the common noun of the verb “thy father is sick” (Gen. 48:1); “when they were sick” (Psa. 35:13).
The 53rd Psalm is striking, concerning the diseased state of the nation, and its importance as a Psalm is seen in its being given a second time in the book, but slightly altered (see Psa. 14).
The word Mahalath also occurs with Leannoth, after it (Psa. 88), which may be the plural of the word rendered Wormwood (Deut. 29:18; Prov. 5:4; Jer. 9:15; 23:15), and Hemlock (Amos 6:12) — unless Leannoth be a proper name, concerning the sickness of Leannoth; concerning the disease of wormwood (i.e. the deadly, bitter disease), which would suit the Psalm.
The LXX. divided Leannoth into le the preposition to, and sing, respond to; and consider Mahalath either a proper name, of a tune, or instrument to sing on, or to Mahalath. I prefer the other.
10. Maschil. Translated in margin, “or giving instruction.”
There are thirteen of these Psalms, namely: — 32, 42, 44, 45, 52, 53, 54, 55, 74, 78, 88, 89, 142.
As the translators have given a rendering here, I say no more than, that their side readings (as found in King James’ Bible) are as authoritative as their text, and of far more value than modern “lit,” which are often worse than nonsense. As a whole, their translation is as wonderful as is the mercy which God has shown to this land, in connection with it, as above that of other lands.
11. The Michtam Psalms are 16, 56, 57, 58, 59, and 60.
I know no better rendering than the common one, a golden psalm. The word Michtam occurs nowhere else: but the word rendered, in gold of Ophir (Psa. 45:9); and golden wedge (Isa. 13:12) is a kindred word, and occurs nine times, as gold, and in no other sense.
12. Muth-labben. Psalm 9 title.
Muth (Psa. 48:14), “our guide unto death.
La, for the; ben, son. “Concerning death for the Son.”
The LXX. concerning the secret things of the Son.
13. Neginah, of which Neginoth is the plural.
“I am their song” (Job 30:9), “song” (Psa. 69:12; 77:6; Isa. 38:20; Lam. 3:14), “music” (Lam. 5:14), “on my stringed instruments” (margin, neginoth) (Hab. 3:19), shows the meaning plainly enough. The verb is to strike the strings. Neginah occurs in Psalm 61 Title; Neginoth, Psalms 4, 6, 54, 55, 67, 76. Upon the stringed instrument, or upon the stringed instruments.
14. Nehiloth. Psalm 5.
The pipes, or flutes, as commonly derived from the verb, to pierce.
15. Selah occurs seventy times in the Psalms, and three times in Habakkuk.
All sorts of tortures have been inflicted on this word, to make it speak. Some take its three consonants as the first letters of three words, and render it as equivalent to our da cape, in music: let the musician return. But this is very unlike old Hebrew.
Gesenius says it is Silence, supposing it equivalent to the words, at rest, (Dan. 4:4); as if Shelah and Selah were the same. Though I desire to read with shoes off my feet (for the place is holy, and I dread conjectures), it might, according to kindred words, mean raising. And so silence, as the result of one’s rising from singing; for the idea of weighing is found in Lamentations 4:2; in a good sense comparable to gold: and also, in a bad sense, (Psa. 119:118), trodden down.
I observe that Selah is put often where a pause is natural, as after some peculiar statement: and thus, practically, I feel that it is pause, or silence, with Gesenius. More I cannot say.
16. Sheminith occurs 1 Chronicles 15:21; and in the titles of Psalms 6 and 12.
The translator’s margin gives, on the eighth. It is the common ordinal adjective for eight, and refers to strings of instruments.
Some render it Octave, as denoting that it is to be played an octave lower than it is written; so, I think, Gesenius. I prefer the margin.
Observe that in 1 Chronicles 15:20 and 21, Alamoth and Sheminith are in contra-position.
17. Shiggaion, Psalm 7, and Habakkuk 3:1, Shigionoth in the plural.
The verb is, to err, (Psa. 119:10,21,118); sin through ignorance (Lev. 4:13). A wandering ode — an ode of wandering.
Variable songs — songs with variations. But I prefer either of the former.
18. Shoshannim. The lilies, as in Song of Solomon 2:16; 4:5. Occurs in the titles of Psalms 45 and 69, and in Psalm 80 (in connection with Eduth).
Shushan-Eduth (Psa. 40) is the same word nearly, it occurs only 1 Kings 7:19, lily. Eduth is the common word for the testimony, in Exodus, etc. The lily is supposed to refer to an instrument, from its shape: so, I think, Calmet. Others connect it with the name of a song.
The word for upon, may just as well be rendered concerning to, etc.

Jackson’s Dictionary of Scripture Proper Names:

lilies