arcade vs colonnade

arcade and colonnade both are nouns.

Word	Noun	Adjective	Verb	Adverb
arcade	Yes	No	No	No
colonnade	Yes	No	No	No

As nouns, arcade and colonnade are synonyms defined as:

arcade and colonnade: a structure composed of a series of arches supported by columns

arcade (noun)	colonnade (noun)
a structure composed of a series of arches supported by columns	structure consisting of a row of evenly spaced columns
a covered passageway with shops and stalls on either side	a structure composed of a series of arches supported by columns