Big name in bricks (4)
I believe the answer is:
lego
'big name in bricks' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for lego that I've seen before include "Child's plastic construction set" , "Toy consisting of interlocking plastic bricks" , "constructed without care" , "Toy building-bricks" , "Building bricks for children" .)