From the primary kapto (in the sense of seizing); the head (as the part most readily taken hold of), literally or figuratively -- head.

κεφαλαὶ (kephalai) − 3 Occurrences

κεφαλὰς (kephalas) − 13 Occurrences

κεφαλῇ (kephalē) − 15 Occurrences

κεφαλὴν (kephalēn) − 28 Occurrences

κεφαλῆς (kephalēs) − 15 Occurrences

κεφαλῶν (kephalōn) − 1 Occurrence