Definify.com
Webster 1913 Edition
Theca
‖
1.
A sheath; a case;
as, the
theca
, or cell, of an anther; the theca
, or spore case, of a fungus; the theca
of the spinal cord.2.
(Zool.)
(a)
The chitinous cup which protects the hydranths of certain hydroids.
(b)
The more or less cuplike calicle of a coral.
(c)
The wall forming a calicle of a coral.