Subsidiary activity making team row (8)
I believe the answer is:
sideline
'subsidiary activity' is the definition.
(I've seen this before)
'team row' is the wordplay.
'team' becomes 'side' (both can mean a sports team).
'row' becomes 'line' (as in a row of things).
'side'+'line'='SIDELINE'
'making' is the link.
(Other definitions for sideline that I've seen before include "Secondary activity" , "hobby" , "not my main interest" , "Secondary job" , "Activity outside one's main job" .)