One with limited freedom to ride the waves, say (4)
I believe the answer is:
Here is my best explanation:
'one with limited freedom' is the definition.
'ride the waves say' is the wordplay.
'ride the waves' becomes 'surf' (I've seen this before).
'say' shows a homophone (sound like).
'surf' is a homophone of 'SERF'.
'to' is the link.