I'll Be A Monkey's Uncle

Subscribe to Idioms Online on YouTube

Privacy | Contact

Subscribe to Idioms Online on YouTube

Meaning of Idiom 'I'll Be a Monkey's Uncle'

I'll be a monkey's uncle is an expression used to indicate surprise, astonishment, amazement, shock, and sometimes disbelief or skepticism. 1,2,3


This idiom can be used to express mild or extreme emotions and is often used in a slightly sarcastic way, to feign surprise, as in the first example, below. The word well or why often precedes the phrase.


"John asked me if he could borrow money to pay his rent, he spent his on a new guitar," said Maria. "John spent his rent money? Well, I'll be a monkey's uncle. Not John!" replied Greg.

"The president wants to get us back into space," said Ben. "Well I'll be a monkey's uncle," said Tony, "didn't he just slash the NASA budget in half?"

"I'll be a monkey's uncle. We're halfway through April and it's snowing outside."



The idiom I'll be a monkey's uncle began as a sarcastic response to Charles Darwin's theory of evolution. After Darwin published The Origin of Species in 1859, the foundation of the evolutionary theory, he published The Descent of Man in 1871. In this book, he made the shocking claim that man had descended from apes, and, in fact, was closely related to modern apes. This claim was, of course, considered ridiculous and offensive, since most people believed that man was created by God. Although it is unclear who originally coined the phrase, "well, I'll be a monkey's uncle" became a popular response to Darwin's theory. 2 This phrase was later extended to general use as an expression of great doubt or disbelief. Today, it is more often used to express surprise or shock, often in response to quite mild revelations.

1. Ayto, John. Oxford Dictionary of English Idioms. Oxford: Oxford U, 2010.
2. Thompson, Andrew. Hair of the Dog to Paint the Town Red: The Curious Origins of Everyday Sayings and Fun Phrases. Ulysses Press, 2017.
3. Spears, Richard A. McGraw-Hill's American Idioms Dictionary. Boston: McGraw Hill, 2008.

More Surprise Related Idioms
Taken Aback, to be

More Surprise Related Idioms

More Uncle Idioms

More Uncle Idioms

This page contains one or more affiliate links. See full affiliate disclosure.

© 2018 by IdiomsOnline.