Colonnade (6)
'colonnade' is the definition.
(synonyms)
This is the entire clue.
(Other definitions for arcade that I've seen before include "Covered passage containing shops" , "Shopping passage" , "Covered way with shops on either side" , "where 'penny' often drops" , "shopping precinct" .)
'colonnade' is the definition.
(I've seen this before)
This is all the clue.
(Other definitions for portico that I've seen before include "covered area" , "Classical porch" , "Posh covered entrance to building" , "Covered porch with supporting columns" , "Grand porch" .)