The term “donkey’s years” is an idiomatic expression in English that means “a very long time.” Its origins are a bit murky, but there are a couple of plausible explanations tied to linguistic evolution and cultural references.
One theory suggests it comes from British slang in the late 19th or early 20th century. “Donkey” was often used to describe something stubborn, slow, or enduring—traits associated with the animal. The phrase might have started as “donkey’s ears,” playing on the idea of a donkey’s long ears as a metaphor for a long duration. Over time, through rhyming slang or simple mishearing, it morphed into “donkey’s years.” Cockney rhyming slang, where “years” could rhyme with “ears,” supports this idea, though there’s no definitive proof.
Another possibility is that it reflects the donkey’s reputation for a long lifespan or its use as a work animal over many years, symbolizing an extended period. Farmers and laborers might have coined it to exaggerate time in a humorous way, like saying, “I haven’t seen you in donkey’s years!”
The earliest recorded uses appear in British English around the early 1900s. For example, it pops up in wartime slang from soldiers, suggesting it was already familiar by then. Today, it’s still used informally—think “I haven’t been here in donkey’s years”—to emphasize a stretch of time that feels almost comically long and it likely grew out of donkey-related imagery mixed with playful language
