ăcĕphălus — Lewis & Short
ăcĕphălus, i, adj., = a)ke/falos.
I Without head, without chief or leader.— Subst.: ăcĕphăli, a sect of heretics, Isid. Or. 8, 5, 66; cf. 5, 39, 39 sq.—
II In prosody, of a hexameter which begins with a short syllable (e. g. e)peidh/), Vel. Long. p. 2219 P.