Play around in Leatherhead, obviously (7)
I believe the answer is:
plainly
'obviously' is the definition.
(I've seen this before)
'play around in leatherhead' is the wordplay.
'around' indicates putting letters inside.
'leatherhead' becomes 'l' (head letter of 'leather').
'in'+'l'='inl'
'play' placed around 'inl' is 'PLAINLY'.
(Other definitions for plainly that I've seen before include "... without embellishment" , "Clearly" , "In unconcealed fashion" , "obviously" , "Simply" .)