Seaside attraction or something to eat by river (4)
I believe the answer is:
pier
'seaside attraction' is the definition.
(structure by the sea)
'something to eat by river' is the wordplay.
'something to eat' becomes 'pie' (pie is a kind of food).
'by' is a charade indicator (letters next to each other).
'river' becomes 'r' (abbreviation).
'pie'+'r'='PIER'
'or' is the link.
(Other definitions for pier that I've seen before include "Seaside attraction" , "Structure with a deck, built over water" , "Landing-stage or promenade" , "Support member" , "Ripe as a jetty (4)" .)