means A large, fan-tailed game bird native to the Americas, now the centerpiece of many holiday dinners — and, by extension, slang for a flop or a foolish person.

from The name is a geographic mix-up. Europeans first encountered a similar-looking bird, the African guinea fowl, imported through Turkish-controlled lands, and dubbed it the 'turkey cock.' When the actual American bird arrived, the name simply transferred to it — so this thoroughly New World creature ended up named for a country it never saw. The 'flop' sense comes from 20th-century American theater slang, where a failed show was a 'turkey,' possibly from cheaply produced plays staged around Thanksgiving.