noun, plural the·cae [thee-see] /ˈθi si/.
- a sac, cell, or capsule.
- a sporangium.
Origin of theca
Examples from the Web for thecal
These two types are, in the main, correlated with two gradual differentiations in the minute structure of the thecal plates.
At the same time the thecal plates degenerated into spicules.
The brachia rise from a corresponding number of thecal plates, “radials (RR).”