Usage: 3 forms in 3 verses
Form Translated As     In Verse(s)
φονοκτονεί by murder LXX.Num.35.33
φονοκτονήσητε should you pollute with murder LXX.Num.35.33
εφονοκτονήθη was polluted with murder LXX.Ps.106.38

Liddell-Scott-Jones

φονοκτονέω (phonoktoneō) to pollute with murder G:V

φονοκτονέω-κτονέω,

pollute with murder or blood, [LXX]

LSJ Scripture Refs: LXX.Num.35.33LXX.Ps.105.38*