Meaning of throat sac in English:
throat sac
noun
A distensible pouch of skin in the throat of an animal, used especially for catching prey (as in pelicans), display (as in certain birds), or vocalization (as in male frogs and some apes).
Also called gular sac or (in frogs) vocal sac.
Origin
Early 19th century.
Are You Learning English? Here Are Our Top English Tips