Dewlap

A dewlap is a longitudinal flap of skin or similar flesh that hangs beneath the lower jaw or neck of many vertebrates.

More loosely, it can be various similar structures in the neck area, such as those caused by a double chin or the submandibular vocal sac of a frog.

Dewlaps can be considered as a caruncle, defined as "a small, fleshy excrescence that is a normal part of an animal's anatomy".

There also seems to be a cognate to Danish dialectal doglæp ("flap of skin that sweeps dew from grass, especially on the neck of an ox"),[2] but this might be a parallel independent development.

From the 1580s onward, it was applied to the fleshy fold or wattle of a turkey and also to a flaccid, elderly human throat.

In laboratory conditions, when a butyl alcohol extract of the urine of pregnant women was administered to male rabbits, they developed a dewlap, which then gradually disappeared once the administration ceased.