Imbecile

DODO

This flightless bird went extinct in the 17th century and is now a symbol of obsolescence or foolishness.

"Imbecile" is a playful dig at the dodo, a flightless bird famously known for its extinction—often seen as a symbol of stupidity because it didn’t adapt quickly enough. The clue leans on the bird’s reputation as a dumb or doomed creature, using "imbecile" to hint at the answer. It’s a straightforward insult-to-animal reference, common in crosswords where words double as teasing nicknames. Think of it like calling someone a "turkey" for being silly, but with a historical twist.