Ring and laugh at work (4)
I believe the answer is:
hoop
'ring' is the definition.
(I know that ring can be written as hoop)
'laugh at work' is the wordplay.
'laugh' becomes 'ho' (representation of a laughing sound).
'at' is a charade indicator (letters next to each other).
'work' becomes 'op' (abbreviation for opus).
'ho'+'op'='HOOP'
'and' acts as a link.
(Other definitions for hoop that I've seen before include "Rigid circular band" , "children's toy" , "Circle, ring" , "Metal ring for croquet and basketball" , "Circle of wood etc" .)