It's put in by an attendant (10)

I believe the answer is:

appearance

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'put in by an attendant' is the definition.
The definition and answer can be both acts as well as being singular nouns.
Maybe they are linked in a way I don't understand?

I don't understand the remainder of the clue.

Can you help me to learn more?

(Other definitions for appearance that I've seen before include "Advent" , "it seems" , "Act of being present - look" , "Semblance" , "manifestation" .)

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

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