Fuel has a way in by the sea (7)
I believe the answer is:
coastal
'by the sea' is the definition.
(by the coast)
'fuel has a way' is the wordplay.
'fuel' becomes 'coal' (coal is a kind of fuel).
'has' means one lot of letters goes inside another.
'way' becomes 'st' (short for street).
'a'+'st'='ast'
'coal' going around 'ast' is 'COASTAL'.
'in' is the link.
(Other definitions for coastal that I've seen before include "near the seaside" , "Near the sea" , "To do with ribs" , "on the beach?" , "Adjoining the sea" .)