Main team in coastal area (7)
I believe the answer is:
seaside
'coastal area' is the definition.
(I've seen this before)
'main team' is the wordplay.
'main' becomes 'sea' (the main is an old name for the sea).
'team' becomes 'side' (both can mean a sports team).
'sea'+'side'='SEASIDE'
'in' acts as a link.
(Other definitions for seaside that I've seen before include "Popular resort area" , "leisure area" , "Holiday place" , "Disease (anag) -- coast" , "holiday venue" .)