/ep'euh nik"ee euhm/ , n. , pl. eponychia /-nik"ee euh/
1. Embryol. the modified outer layer of the epidermis that partially covers the fetal fingernails and toenails and that persists after birth as the cuticle.
2. Anat. a thin, cuticular fold extending over the lunula of a nail.
Also, epionychium .
[ 1880-85; ep- EP- + onych- (see ONYX) + -ium -IUM ]