RUKM! 

A word standing for "Are you kidding me?"- an expression commonly used by people to express their exasperation during an OMG type situation.

Kona Grill no longer has reverse happy hour, RUKM!

RUKM! by Crumbs. October 7, 2010

RUKM 

A texting/IMing abbreviation for "are you kidding me?"

When said out loud, it is pronounced roo-kum.

Alex: So I started going out with Laura.

Joey: RUKM?! I thought you hated her!

-or-

Martin: I got a 58 on my math test?! RUKM! I studied all night for that!

RUKM by mrwaters_algebra_period2 October 31, 2009