anus
n. countablen. the opening at the end of the digestive system where solid waste leaves the body.
n. the distal opening of the alimentary canal through which solid waste is excreted from the body.
During a routine physical exam, the veterinarian inspected the dog's anus for any abnormalities or blockages.
The evolution of a complete digestive tract, ending in a functional anus, allowed early organisms to process nutrients more efficiently than those with a single-opening system.
Either from Middle French anus or Latin ānus (“ring, anus”), from Proto-Indo-European *h₁eh₂no- (“ring”). First attested in 1658. See also anal, annular, annelid.
Primarily used in medical, biological, or anatomical contexts; often replaced by slang or euphemisms in casual conversation.