Critical remark made by stalwart over club (8)
I believe the answer is:
brickbat
'critical remark' is the definition.
(I've seen this before)
'stalwart over club' is the wordplay.
'stalwart' becomes 'brick' (I've seen this in other clues).
'over' says to put letters next to each other.
'club' becomes 'bat' (I've seen this before).
'brick'+'bat'='BRICKBAT'
'made by' is the link.
(Other definitions for brickbat that I've seen before include "(Critic's) weapon" , "Piece of blunt criticism" , "Building block used as missile" , "Strong criticism" , "Hostile criticism - missile" .)