Sailor meeting with spooks, barring a no-show (7)

I believe the answer is:

absence

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'sailor meeting' 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 rest of the clue.

Can you help me to learn more?

(Other definitions for absence that I've seen before include "What supposedly makes the heart grow fonder?" , "Failure to attend" , "Non-presence" , "Want (of something)" , "Need" .)

I've seen this clue in The Independent.

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