All in

Meaning

Fully committed to an action.

Usage

Borrowed from gambling but now general for total commitment.

Origin & History

Origins and dates here are approximate summaries. Many idioms have disputed or unknown origins, and not every date has been checked against a historical dictionary, so treat specific dates and stories as a starting point rather than a citation.

Poker term for betting everything.

Mid-20th-century expansion from card games to everyday use.