A person with unvaried interests. These types of people usually try to appear interesting through their choice of clothes or music however, conversation with one of these people is absolutely dull.
"He's such a onetone, he always finds a way to talk about the alien argot of the avant-garde."

"My BF sucks, he's a onetone."
by puppiesncream January 16, 2012
Get the onetone mug.