'Rictus' definitions:

Definition of 'rictus'

From: WordNet
noun
A gaping grimace

Definition of 'Rictus'

From: GCIDE
  • Rictus \Ric"tus\, n. [L., the aperture of the mouth.] The gape of the mouth, as of birds; -- often resricted to the corners of the mouth. [1913 Webster]