popoff

[ pop-awf, -of ]
/ ˈpɒpˌɔf, -ˌɒf /
Slang.

noun

a person who generally speaks loudly or irately; indiscreet arguer or complainer.

adjective

pertaining to or characteristic of such a person: His popoff remarks cost him many friends.

Origin of popoff

First recorded in 1940–45; noun, adj. use of verb phrase pop off