betrayer, traitor

Concise Bible Dictionary:

This signifies one who “delivers up,” “betrays.” It is applied to Judas, who delivered up his Lord (Luke 6:16). In 2 Timothy 3:4 some having a form of godliness are thus designated, the reference may be to secret agents of Satan who betrayed the saints. Stephen charged the council with being the betrayers (the same Greek word) and murderers of the Just One (Acts 7:52).
In the early church there were some so called (under the Latin name Traditores), because under persecution they gave up the copies of the scriptures or church property, to save their lives; and there was long contention as to whether such could ever be restored to communion.

Strong’s Dictionary of Greek Words:

Greek:
προδότης
Transliteration:
prodotes
Phonic:
prod-ot’-ace
Meaning:
from 4272 (in the sense of giving forward into another's (the enemy's) hands); a surrender
KJV Usage:
betrayer, traitor