RhymeZone: acephalic definitions

Definitions of acephalic:

adjective: Without a head.
adjective: (medicine, of a headache, dated) Characterized by a migraine aura without pain.
adjective: Without a leader.
adjective: (prosody) Deficient in the beginning, as a line of poetry that is missing its expected opening syllable.
adjective: (of a manuscript) Lacking the first portion of the text.

(Definitions from Wiktionary)