Sign bricks no good (3)
I believe the answer is:
leo
'sign' is the definition.
(Leo is an example)
'bricks no good' is the wordplay.
'bricks' becomes 'lego' (I have seen 'Small bricks' mean 'lego' so perhaps 'bricks' could also mean 'lego').
'no' is a deletion indicator.
'good' becomes 'g' (abbreviation).
'lego' with 'g' taken out is 'LEO'.
(Other definitions for leo that I've seen before include "Star sign of one born on August 1" , "5th sign of the zodiac" , "MGM's lion" , "Name taken by 13 popes, the last dying in 1903 aged 93" , "Cancer, ___, Virgo" .)