All together in Paris? (2,5)

I believe the answer is:

en masse

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'all together' is the definition.
(I've seen this in another clue)

I don't understand the remainder of the clue.

(Other definitions for en masse that I've seen before include "As a body (Fr.)" , "All together (Fr.)" , "as a bunch" , "All together as a group" , "In a group U altogether" .)

I've seen this clue in The Sun.

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