noun, plural ric·tus, ric·tus·es.
- the gape of the mouth of a bird.
- the gaping or opening of the mouth.
noun plural -tus or -tuses
- the gap or cleft of an open mouth or beak
- a fixed or unnatural grin or grimace, as in horror or death
noun, plural ric·tus, ric·tus·es.
noun plural -tus or -tuses