Seaside walk pleased an eccentric (9)
I believe the answer is:
esplanade
'seaside walk' is the definition.
(I've seen this before)
'pleased an eccentric' is the wordplay.
'eccentric' indicates an anagram.
'pleased'+'an'='pleasedan'
'pleasedan' is an anagram of 'ESPLANADE'.
(Other definitions for esplanade that I've seen before include "Seaside resort walk" , "Seaside walkway" , "A leap ends (anag) - seaside feature" , "Seafront walkway" , "front" .)