noun, plural the·cae [thee-see] /ˈθi si/.
- a sac, cell, or capsule.
- a sporangium.
Origin of theca
Related formsthe·cal, adjective
Examples from the Web for theca
A chronic inflammatory involvement of a theca through which an important tendon plays may cause adhesions to form.Lameness of the Horse|John Victor Lacroix
The theca became sessile, and in its later developments much flattened (fig. 11).
The pear-shaped body is encased in a theca formed by a number of polygonal plates, and is attached by its narrow end.
This theca grows in the direction of the apex of the sicula, to which it adheres by its dorsal wall.
Horizontal plates or floors found in some Corals, extending across the cavity of the "theca" from side to side.The Ancient Life History of the Earth|Henry Alleyne Nicholson