Location for a bank holiday? (9)

I believe the answer is:

riverside

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'holiday?' is the definition.
Although both the answer and definition are singular nouns, I can't see how they can define each other.

'location for a bank' is the wordplay.
'location for' becomes 'river' (I can't justify this - if you can you should believe this answer much more).
'a bank' becomes 'side' (synonyms).
'river'+'side'='RIVERSIDE'

Can you help me to learn more?

(Other definitions for riverside that I've seen before include "Bank" , "Area along, say, the Thames" .)

I've seen this clue in The Globe and Mail.

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