Lexical Definition

‎κατεσθίω‎ katesthíō (kat-es-thee'-o) to devour ^G:V
from ‎κατά‎ and ‎ἐσθίω‎ (including its alternate)

devour.

• to eat down, i.e. devour (literally or figuratively)

Abbott-Smith

κατ-εσθίω ("perfective" comp. of ἐσθίω, q.v., and cf. M, Pr., 111), [in LXX chiefly for אכל;]
to eat up, devour: c. acc., of seed, Mt 13:4, Mk 4:4, Lk 8:5; τέκνον, Re 12:4; βιβλαρίδιον, Re 10:9, 10; metaph., οἰκίας, Mt 23:13, Mk 12:40, Lk 20:47; τ. βίον, Lk 15:30; c. acc. pers., Jo 2:17(LXX), II Co 11:20, Ga 5:15, Re 11:5 20:9.†

Abbott-Smith References

Liddell-Scott-Jones

κατεσθίω,

poetry and later κατερῡκ-έσθω [NT+5th c.BC+] (passive, 1.5, [Refs 4th c.AD+]: future κατέδομαι [Refs 8th c.BC+]aorist κατέφαγον (see. καταφαγεῖν): perfect κατεδήδοκα [Refs]; participle κατὰ.. ἐδηδώς [Refs 8th c.BC+]:—passive, perfect κατεδήδεσμαι [Refs 5th c.BC+]: aorist κατηδέσθην [Refs 5th c.BC+]:—eat up, devour, in [Refs 8th c.BC+] frequently of animals of prey, λέων κατὰ ταῦρον ἐδηδώς [Refs 8th c.BC+]; of a serpent, [νεοσσοὺς] κατήσθιε [Refs 8th c.BC+]; of a dolphin, κατεσθίει ὅν κε λάβῃσιν [Refs 8th c.BC+]; also of men, οἳ κατὰ βοῦς.. ἤσθιον [Refs 8th c.BC+]; τοὺς γονέας [Refs 5th c.BC+]; κατεδηδόκασι τὰ λάχαν᾽ [Refs 5th c.BC+]

__2 eat up, devour one's substance, τὰ κοινά, τὰ πατρῷα, [Refs 5th c.BC+]
__3 corrode, [ῥεύματα] κ. γνάθους [Refs 5th c.BC+]; λίθοι κατεδηδεσμένοι ὑπὸ σηπεδόνος Pl.[same place],[Refs 5th c.BC+]; of the wind, κ. τὰ ἄνθη [Refs 4th c.BC+]:—passive, to be gnawed, [Refs]
__4 bite, τοῦ παλαιστοῦ τὸ οὖς [Refs 2nd c.AD+]
__5 κ. ἑαυτόν, metaphorically, of remorse, [Refs 4th c.AD+]

_{LSJ Scripture Refs: Mark.12.40}