Usage: 2 forms in 2 verses
Form Translated As     In Verse(s)
ενεκότουν they displayed anger LXX.Ps.55.3
ενεκότει Esau was angry LXX.Gen.27.41

Liddell-Scott-Jones

ἐγκοτέω (egkoteō) be angry G:V

ἐγκοτέω-έω,

to be indignant at, τινί [LXX+5th c.BC+]

LSJ Scripture Refs: LXX.Gen.27.41