Dictionary entry

καθήκω

G. Abbott-Smith's A Manual Greek Lexicon of the New Testament

καθ-ήκω,

[in LXX: impers., Le 5:10, Ez 21:27 (32), al. (מִשְׁפָּט); τὰ κ., Ex 5:13, al. (דָּבָר), etc.;]

1. to come down, come to.

2. to be fit, proper: impers., c. acc. et inf., Ac 22:22 (on the tense, v. Bl., § 63, 4); τὰ μὴ καθήκοντα, Ro 1:28.†