Shorter term of shitting bricks when one is nervous.
Muscle Man Randy Savage is brickin it because he's about to get pulverized by The Rock.
by UNVME666 November 22, 2011
1 more definition
v. to be extremely erect and have so much blood flow in your genitals that you are hard as a brick
Justin was brickin' it in the scholastic bowl van around noon that Saturday.
by Raptor Jesus April 22, 2007