The Collaborative International Dictionary of English v.0.48:

nympha \nym"pha\, n.; pl. Nymphae. [L. See Nymph a goddess.]
   1. (Zool.) Same as Nymph, 3.
      [1913 Webster]

   2. pl. (Anat.) Two folds of mucous membrane, within the
      labia, at the opening of the vulva.
      [1913 Webster]