slang To be very scared or nervous. (A reference to the more vulgar phrase "shitting bricks.") Of course I was bricking it when I woke up to the sounds of an intruder in my house!

What does bricking it mean in slang?

From Longman Dictionary of Contemporary English be bricking itBritish English informal to feel very nervous or frightened → brick. Exercises.

Where does the saying bricking it come from?

Bricking it is derived from shitting a brick, meaning being very afraid.