One Goth could become so active (2,3,2)
I believe the answer is:
on the go
'active' is the definition.
(I've seen this in another clue)
'one goth could become' is the wordplay.
'could become' indicates anagramming the letters.
'one'+'goth'='onegoth'
'onegoth' with letters rearranged gives 'ON THE GO'.
'so' acts as a link.
(Other definitions for on the go that I've seen before include "Keeping busy, not stopping" , "Ever busy" , "Moving -- active" , "Very active (colloq.)" , "Very busy, in constant motion" .)