STEP Greek Lexicon: ἔθω

ἔθω, pf. with present sense εἴωθα,

[in LXX: Num.24:1 (כְּפַעַם־בְּפַעַם), Dan LXX Su 13, Sir.37:14, 4Ma.1:12 * ;]

to be accustomed, wont: Mat.27:15, Mrk.10:1; ptcp., τὸ εἰθός, custom: κατὰ τὸ εἰ. (Nu, l.with), Luk.4:16, Act.17:2.†

(AS)