What does "acephalous" mean?

Acephalous: (Zoöl.) Without a distinct head; -- a term applied to bivalve mollusks.

Additional senses

  1. 2.(Bot.) Having the style spring from the base, instead of from the apex, as is the case in certain ovaries.
  2. 3.Without a leader or chief.
  3. 4.Wanting the beginning. A false or acephalous structure of sentence. De Quincey.
  4. 5.(Pros.) Deficient and the beginning, as a line of poetry. Brande.

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