Spontaneous routine (7)

I believe the answer is:

natural

I believe this clue is a double definition.

'spontaneous' is the first definition.
(synonyms)

'routine' is the second definition.
(thesaurus)

(Other definitions for natural that I've seen before include "Regular" , "Illegitimate" , "Unforced" , "Sign on staff" , "Fuel from underground" .)

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

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