Working after shift carrying large club (8)
I believe the answer is:
bludgeon
'club' is the definition.
(bludgeon is a kind of club)
'working after shift carrying large' is the wordplay.
'working' becomes 'on'.
'after' says to put letters next to each other.
'shift' becomes 'budge' ('budge' can be a synonym of 'shift'**).
'carrying' indicates putting letters inside.
'large' becomes 'l'.
'budge' placed around 'l' is 'bludge'.
'on' put after 'bludge' is 'BLUDGEON'.
(Other definitions for bludgeon that I've seen before include "Bully; heavy weapon" , "Short stick with thickened end as weapon" , "Beat repeatedly with a heavy object" , "Cudgel" , "Stick or club with a heavy end" .)