from
The Collaborative International Dictionary of English v.0.48
Acephalocyst \A*ceph"a*lo*cyst\, n. [Gr. 'ake`falos without a
head + ky`stis bladder.] (Zool.)
A larval entozo["o]n 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]