Yeyeah is a totally awsome word used used by super cool guys like James Hetfield or Dave Mustaine. It is used to show that they really mean what they are singing and that they are really cool. YEYEAH!!!!!111!!!11
"Made my ball bearing melt from the heat
wow, yeyeah" Dave mustaine singing Mechanix
"Never cared for what they do
Never cared for what they know
And I know
YEYEAH" James Hetfield in Nothing Else Matters
a word to show agreement. usually used when someone asks a question.
hey homie, checkin out the club?