Usage: 2 forms in 2 verses
Form Translated As     In Verse(s)
καταθύμιον wish LXX.Mic.7.3
καταθύμια their wishes LXX.Isa.44.9

Liddell-Scott-Jones

καταθύμιος (katathumios) wishes G:A

καταθύμιος [], α, ον,

also ος, ον [Refs 8th c.BC+]:— in the mind or thoughts, ὄφρα ἔπος εἴπωμι τό μοι καταθύμιόν ἐστιν [Refs 8th c.BC+]; μηδέ τί τοι θάνατος κ. ἔστω let not death sit heavy on thy heart, [Refs 8th c.BC+]

__II according to one's mind, τῷ Ἰθωμάτᾳ κ. ἔπλετο Μοῖσα [Refs 8th c.BC+]; ἐούσης ταύτης [γυναικός] οἱ καταθυμίης [Refs]; τί γὰρ ἥδιον ἀνθρώπῳ γυναικὸς καταθυμία; [LXX+5th c.BC+]

LSJ Scripture Refs: LXX.Isa.44.9LXX.Mic.7.3