Blunt criticism of decent chap joining club (8)
I believe the answer is:
brickbat
'blunt criticism' is the definition.
(I've seen this before)
'decent chap joining club' is the wordplay.
'decent chap' becomes 'brick' (I've seen this in other clues).
'joining' says to put letters next to each other.
'club' becomes 'bat' (bat is a kind of club).
'brick'+'bat'='BRICKBAT'
'of' acts as a link.
(Other definitions for brickbat that I've seen before include "Strong criticism" , "Hostile criticism - missile" , "Piece of blunt criticism" , "Building block used as missile" , "Highly critical remark" .)