Muddled men, fools, not quite together (2,5)
I believe the answer is:
en masse
'together' is the definition.
(French phrase meaning all together)
'muddled men fools not quite' is the wordplay.
'muddled' indicates anagramming the letters.
'fools' becomes 'asses' (ass is a kind of fool).
'not quite' means to remove the last letter.
'asses' with its last letter removed is 'asse'.
'men' anagrammed gives 'enm'.
'enm'+'asse'='EN MASSE'
(Other definitions for en masse that I've seen before include "All together as a group" , "As a body (Fr.)" , "All together (Fr.)" , "All together - in France (2.5)" , "Many as one" .)