/euh nap"sid/ , adj.
1. belonging or pertaining to the Anapsida, a subclass of reptiles, extinct except for the turtles, characterized by having no opening in the temporal region of the skull.
n.
2. a reptile of the subclass Anapsida. Cf. diapsid .
[ 1930-35; Anapsida, equiv. to an- AN- 1 + -apsida, pl. of -apsidum, neut. adj. deriv. of Gk apsís, hapsís loop, arch (referring to the opening in the skull); see APSIS ]