holy cow

interjection

Slang.

1. (used to express bewilderment, surprise, or astonishment.)

Word History and Origins

Origin of holy cow¹

First recorded in 1920–25

Idioms and Phrases

Also,. An exclamation of surprise, astonishment, delight, or dismay, as in Holy cow, I forgot the wine, or Holy mackerel, you won! or Holy Moses, here comes the teacher! or Holy smoke, I didn't know you were here too. The oldest of these slangy expletives uses mackerel, dating from about 1800; the one with Moses dates from about 1850 and cow from about 1920. None has any literal significance, and moly is a neologism devised to rhyme with “holy” and possibly a euphemism for “Moses.”