Football club always associated with heavyweight (7)
I believe the answer is:
everton
'football club' is the definition.
(I've seen this before)
'always associated with heavyweight' is the wordplay.
'always' becomes 'ever' (synonyms).
'associated with' is a charade indicator (letters next to each other).
'heavyweight' becomes 'ton' (a ton weighs a lot).
'ever'+'ton'='EVERTON'
(Other definitions for everton that I've seen before include "One side in blue" , "'The Toffees' FC" , "Premiership football team" , "Merseyside soccer team" , "Football team whose home is Goodison Park" .)