Usage: 2 forms in 4 verses
Form Translated As     In Verse(s)
εγκάτοισ my insides LXX.Ps.51.10
έγκατα his insides LXX.Job.21.24LXX.Job.41.15LXX.Ps.109.18

Liddell-Scott-Jones

ἔγκατα (egkata) insides G:N-N

ἔγκατα, τά,

inwards, entrails, [Refs 8th c.BC+] always in accusative, as [LXX+8th c.BC+]

LSJ Scripture Refs: LXX.1Kgs.17.22