Becoming stuck measuring around bottom of settee (7,2)

I believe the answer is:

seizing up

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'becoming stuck' is the definition.
I know nothing about this answer so I cannot judge whether this works.

'measuring around bottom of settee' is the wordplay.
'measuring' becomes 'sizingup' (I can't explain this - if you can you should believe this answer much more).
'around' is an insertion indicator.
'bottom of' suggests the final letters.
The final letter of 'settee' is 'e'.
'sizingup' placed around 'e' is 'SEIZING UP'.

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I've seen this clue in The Telegraph.

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