The expression “until the cows come home” refers to an indefinite, very long period of time. When someone says they will do something until the cows come home, they imply the action will continue for a duration so extended that the end is not currently in sight.
The phrase dates back to at least the late 16th or early 17th century. It draws from the predictable yet slow nature of cattle. Cows are typically put out to pasture in the morning and do not return to the for milking until the evening or the following morning. Because they move at a leisurely pace and have no reason to hurry, “waiting for the cows” became a figurative way of describing something that would continue for a long time.
Some linguistic historians also suggest it refers to the fact that if cows are not driven home by a farmer, they might stay out for days or weeks.
In use
The customer support agent kept me on hold until the cows come home, yet the software issue remains unresolved.
We can debate the proposal until the cows come home, but we still need a decision today.
