A.T. Robertson Commentary 2 Timothy 2:17

"and their word will eat as doth a gangrene: or whom is Hymenaeus an Philetus;" — 2 Timothy 2:17 (ASV)

Will eat (νομην εξε). "Will have (future active of εχω) pasturage or increase" (νομη, old word from νεμω, to pasture, in N.T. only here and Joh 10:9).

As doth gangrene (ως γαγγραινα). Late word (medical writers and Plutarch), only here in N.T. From γραω or γραινω, to gnaw, to eat, an eating, spreading disease. Hymenaeus is probably the one mentioned in 1 Timothy 1:20. Nothing is known of Philetus.