n. [ Gr. &unr_;; 'a priv. + &unr_; head: cf. F. acéphale, LL. acephalus. ] (Zool.) One of the Acephala. [ 1913 Webster ]

‖n. pl. [ NL., fr. Gr. &unr_;, adj. neut. pl., headless. See Acephal. ] (Zool.) That division of the Mollusca which includes the bivalve shells, like the clams and oysters; -- so called because they have no evident head. Formerly the group included the Tunicata, Brachiopoda, and sometimes the Bryozoa. See Mollusca. [ 1913 Webster ]

n. Same as Acephal. [ 1913 Webster ]

a. (Zool.) Belonging to the Acephala. [ 1913 Webster ]

‖n. pl. [ LL., pl. of acephalus. See Acephal. ] 1. A fabulous people reported by ancient writers to have heads. [ 1913 Webster ]

2. (Eccl. Hist.) (a) A Christian sect without a leader. (b) Bishops and certain clergymen not under regular diocesan control. [ 1913 Webster ]

3. A class of levelers in the time of K. Henry I. [ 1913 Webster ]

n. One who acknowledges no head or superior. Dr. Gauden. [ 1913 Webster ]

n. [ Gr. 'ake`falos without a head + ky`stis bladder. ] (Zool.) A larval entozoön in the form of a subglobular or oval vesicle, or hydatid, filled with fluid, sometimes found in the tissues of man and the lower animals; -- so called from the absence of a head or visible organs on the vesicle. These cysts are the immature stages of certain tapeworms. Also applied to similar cysts of different origin. [ 1913 Webster ]

a. Pertaining to, or resembling, the acephalocysts. [ 1913 Webster ]

a. [ See Acephal. ] [ 1913 Webster ]

1. Headless. [ 1913 Webster ]

2. (Zool.) Without a distinct head; -- a term applied to bivalve mollusks. [ 1913 Webster ]

3. (Bot.) Having the style spring from the base, instead of from the apex, as is the case in certain ovaries. [ 1913 Webster ]

4. Without a leader or chief. [ 1913 Webster ]

5. Wanting the beginning. [ 1913 Webster ]

A false or acephalous structure of sentence. De Quincey. [ 1913 Webster ]

6. (Pros.) Deficient at the beginning, as a line of poetry. Brande. [ 1913 Webster ]