A gangrene or mortification which gradually spreads over the whole body (2 Tim. 2:17). In James 5:3 “cankered” means “rusted” (R.V.) or tarnished.
Canker
1 verse
2 Timothy
2 Timothy 2:17
And their word will eat as doth a canker: of whom is Hymenaeus and Philetus;
From Easton's Bible Dictionary
Matthew George Easton, 1897