rictus

/ˈrɪktəs/
noun
  1. The opening of the mouth or the gape, especially of a bird or animal.
    • The frog's rictus is surprisingly large for its body size.
    • The snake's rictus stretched to swallow the mouse whole.
    • The baby bird opened its rictus wide to receive food from its mother.
  2. A fixed or unnatural grin or grimace, often expressing pain, fear, or tension.
    • She forced a rictus smile for the family photo despite her sadness.
    • His face was frozen in a rictus of terror as the roller coaster plunged.
    • The patient's rictus indicated he was in severe discomfort.
Synonyms
What does "rictus" mean? | whatsthatwordmean | whatsthatwordmean