: an uncouth or rowdy person
About the Word:
Yahoo comes to the English language from the fertile imagination of Jonathan Swift, author of the famed Gulliver's Travels (as well as the somewhat less-remembered Proposal for Correcting, Improving and Ascertaining the English Tongue).
In Gulliver's Travels the Yahoos were an imaginary humanoid race, brutish and uncouth. This book was also responsible for introducing the words Lilliputian and brobdingnagian.
"We are not your ordinary bunch of yahoos." - PC Magazine (advertisement). 24 Dec. 1985
(Source: Merriam-Webster's A Who's Who of literary allusions: words that come from characters in books)