Constriction of edges in this? (8)

I believe the answer is:

thlipsis

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'constriction' is the definition.
I don't know anything about this answer so I can't judge whether it can be defined by this definition.

'edges in this?' is the wordplay.
'edges' becomes 'lips' (lip is a kind of edge).
'in' means one lot of letters goes inside another.
'lips' put inside 'this' is 'THLIPSIS'.

'of' is the link.

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I've seen this clue in The Guardian.

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