FROM STRONG’S GREEK DICTIONARY (1890)

Strong’s Greek Dictionary (1890) — public domain, printed whole.

katheko καθήκω — kath-ay'-ko — from 2596 and 2240; to reach to, i.e. (neuter of present active participle, figuratively as adjective) becoming:-- convenient, fit.

see GREEK for 2596

see GREEK for 2240