Gallivants around playing organs, which will generate issue (6)

I believe the answer is:

gonads

'organs which will generate issue' is the definition.
(gonads are reproductive organs)

'gallivants around playing' is the wordplay.
'gallivants' becomes 'gads' ('gad' can be a synonym of 'gallivant').
'around' indicates putting letters inside.
'playing' becomes 'on' (on can mean playing or performing).
'gads' enclosing 'on' is 'GONADS'.

I've seen this clue in The Guardian.

Want a hint initially instead of a full solution? Install my app