n. A larval entozoon 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.
[医] 无头囊