Usage: 2 forms in 2 verses
Form Translated As     In Verse(s)
καταξανώ I will rend in shreds LXX.Judg.8.7
κατέξανεν he rent LXX.Judg.8.16

Liddell-Scott-Jones

καταξαίνω (kataxainō) to rend in shreds G:V

καταξαίνω,

future -ξᾰνῶ [Refs]:—card, comb well, [Refs 6th c.BC+] Comedy texts 245:—passive, [Refs 5th c.BC+]; πέτρα κατεξαμμένη hollowed out, [Refs 1st c.BC+]

__2 tear in pieces, rend in shreds, [Refs 5th c.BC+]; so κ. τινὰ εἰς φοινικίδα pound him (by stoning) to red rags, [Refs 5th c.BC+] —passive, πέτροισι.. καταξανθεὶς θανεῖν crushed to atoms, [Refs 5th c.BC+].
__3 wear, waste away, [Refs 5th c.BC+]:—passive, [Refs 5th c.BC+]; ὅπλα κατεξάνθαι were worn out by use, [Refs 1st c.BC+].