Form teams, anyway (7)
I believe the answer is:
besides
'anyway' is the definition.
(synonyms)
'form teams' is the wordplay.
'form' becomes 'be' (form can mean to be or constitute).
'teams' becomes 'sides' (eg football sides).
'be'+'sides'='BESIDES'
(Other definitions for besides that I've seen before include "Additionally" , "Anyway" , "What's more" , "Moreover" , "to boot" .)