[ep-uh-nik-ee-uh m]
noun, plural ep·o·nych·i·a [ep-uh-nik-ee-uh] /ˌɛp əˈnɪk i ə/,
  1. Embryology. the modified outer layer of the epidermis that partially covers the fetal fingernails and toenails and that persists after birth as the cuticle.
  2. Anatomy. a thin, cuticular fold extending over the lunula of a nail.

Origin of eponychium

1880–85; < New Latin, equivalent to ep- ep- + onych- (see onyx) + -ium -ium
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018

eponychia in Medicine


  1. An infection affecting the proximal nail fold.


  1. The condensed eleidin-rich areas of the epidermis preceding the formation of nails in the embryo.
  2. The thin skin adhering to the nail at its base.
The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.