A "fat lip" is a common term used to describe an injury where the lip is swollen or bruised, often due to a blow or impact. The phrase is derived from the appearance of a swollen lip, which may appear larger or "fatter" than usual.
Sentences with «fat lip»
let me tell u something, the blue fat lipped dude is in for a shocker 2morro. (justarsenal.com)
It has taken the lake cichlids just 100 generations and as many years to evolve an entirely new physical feature: very fat lips. (newscientist.com)