Boyd’s Bible Dictionary:

(shallow cup). In a general sense any bottle or vessel (1 Sam. 10:1).

Concise Bible Dictionary:

Golden bowls, mentioned in the symbolical language of the Revelation as
1. Containing incense or odors, which are the prayers of saints (Rev. 5:8).
2. Containing the wrath of God. There are seven direct judgments of the wrath of God (they are no longer mere providential actings) upon the settled sphere of God’s dealings, whereby those who have received the mark of the beast are grievously affected; and upon masses of people outside that sphere, and upon the sources of national life and prosperity; also on those in authority in the world; also on the Euphrates, that it may be dried up to make way for the kings from the sun rising; followed by a general break up of human governments introductory to the reign of Christ (Rev. 15:7; Rev. 16:1-17; Rev. 17:1; Rev. 21:9). See REVELATION.