rictus \RIK-tuhs\, noun:
1. The gape of the mouth, as of birds.
2. A gaping grin or grimace.
A rictus of cruel malignity lit up greyly their old bony
--James Joyce, A Portrait of the Artist as a Young Man
His belly swelled grotesquely, his hands curled, his cheeks
puffed out, his mouth contorted in a rictus of pain and
--Tony Horwitz, Confederates in the Attic
Then, as the sympathy and praise engulfed him, Hector would
invariably roll over onto his back, legs in the air, his
mouth twisted into an otherworldly rictus.
--Bruce McCall, "Writers Who Were Really Dogs," New York
Times, June 5, 1994
Rictus is from Latin rictus, "the open mouth," from ringi, "to
show the teeth."