Critical remark
(Other definitions for shot that I've seen before include "Fired or filmed" , "Woven in different colours; attempt to score" , "Crack" , "Gunned down - go - guess" , "Small drink of spirits" .)
'critical remark' is the definition.
(I've seen this before)
This is all the clue.
(Other definitions for brickbat that I've seen before include "An uncomplimentary remark, or kind of missile" , "(Critic's) weapon" , "Hostile criticism - missile" , "Strong criticism" , "Piece of blunt criticism" .)