dog eat dog a situation of fierce competition in which people are willing to harm each other in order to succeed.

☞ This expression makes reference to the proverb dog does not eat dog, which dates back to the mid 16th century in English and before that to Latin canis caninam non est 'a dog does not eat dog's flesh'.

1998Rebecca RayA Certain Age It's dog eat dog, it's every man for himself…Right from the start, fighting amongst ourselves for the few decent wages left.