a phrase used to express agreement or excitement over something. funnier and more exciting than saying "yes" or "sure". this term is most commonly used by hippie surfer dudes with long blonde hair and a surprisingly great tan. even though some people who use this term may seem like complete stoners, they are usually very smart.
Mary: Wanna make pasta later?
Trevor: YEAH MANN!
by swimrgirl8885 November 25, 2010
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