Its the same as damn, but you pronounce the sound of the "Y". You usually say it after something dramatic happens or when some gnarlystuff goes down. The word "son" is put after it lots of times so it makes it sound more buttery.
*some dudedumps his girlfriend*
random on-looker" DAYUMN SON!
*a rapper throws down a sick rhyme"
everyone: DAYUMN NIGGAZ!
Nickname given to bales of marijuana thrown overboard or out of airplanes. Origin is reportedly from members of the US Coast Guard in the area of Southern Florida.
"Base we've got some square groupers floating outside of Miami harbor."