When not working, I had fish (6)
I believe the answer is:
idling
'when not working' is the definition.
The answer and definition can be both to do with social activities as well as being present participle verbs.
Perhaps there's an association between them I don't understand?
'i had fish' is the wordplay.
'i had' becomes 'I'd' (common contraction).
'fish' becomes 'ling' (ling is a kind of fish).
'id'+'ling'='IDLING'
Can you help me to learn more?
(Other definitions for idling that I've seen before include "'Lazing, loafing (6)'" , "Loafing or just ticking over" , "(Engine) ticking over" , "spending lazy time?" , "Doing little or nothing" .)