Freewheel by a lake or by the sea (7)
I believe the answer is:
coastal
'by the sea' is the definition.
(by the coast)
'freewheel by a lake' is the wordplay.
'freewheel' becomes 'coast' (I've seen this in another clue).
'by' says to put letters next to each other.
'lake' becomes 'L' (geographical abbreviation).
'coast'+'a'+'l'='COASTAL'
'or' is the link.
(Other definitions for coastal that I've seen before include "seaboards" , "Near the sea" , "Like seaside resort" , "Of seaside land" , "on the beach?" .)