dewlap (DOO-lap, DYOO-lap) noun
A loose fold of skin hanging under the neck of an animal such as a cow, rooster, lizard, etc. On birds, this appendage is also known as a wattle.
[From Middle English dewlappe; dew, of unknown origin and meaning + lap (fold).]
"Gore is rather more bearish than the last time I saw him, but still handsome, his leonine head beginning to soften with dewlaps, his fiercely intelligent eyes surrounded by innumerable wrinkles."
-- Erica Jong; Into the Lion's Den: Visiting Gore Vidal is No Small Undertaking; The Guardian (London, UK); Oct 26, 2000.