ἑκουσίως
From LSJ
οἴνῳ τὸν οἶνον ἐξελαύνειν → chase out the wine with wine, take a hair of the dog that bit you, try to drive out the wine with wine
English (Strong)
adverb from the same as ἑκούσιον; voluntarily: wilfully, willingly.
English (Thayer)
adverb (from Euripides down), voluntarily, willingly, of one's own accord: ἑκουσίως ἁμαρτάνειν (A. V. to sin willfully) is tacitly opposed to sins committed inconsiderately, and from ignorance or from weakness); 1 Peter 5:2.