Part extemporised, cleverly, just for now (3,3)

I believe the answer is:

pro tem

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'for now' is the definition.
(short for pro tempore, meaning for the time being)

I don't understand how the remainder of the clue works.

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(Other definitions for pro tem that I've seen before include "For the time being, to the old Romans in short" , "For the time being (Latin abbreviation)" , "Temporarily" , "For the present" , "not indefinitely extended" .)

I've seen this clue in the Evening Standard.

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