Dog eat dog

Meaning

Intensely competitive and ruthless.

Usage

Used for cutthroat environments.

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.

The idea is ancient: the Roman scholar Varro wrote that a dog does not eat dog, so a world where it does is ruthless.

The English phrase dates from the 16th century.