Unanimously answer child, returning call (2,3,3)
I believe the answer is:
as one man
'unanimously' is the definition.
(I've seen this in another clue)
'answer child returning call' is the wordplay.
'answer' becomes 'a' (abbreviation eg in Q and A).
'child' becomes 'son' (male child).
'returning' says the letters should be written backwards.
'call' becomes 'name' (as in calling or naming someone something).
'name' in reverse letter order is 'eman'.
'a'+'son'+'eman'='AS ONE MAN'
(Other definitions for as one man that I've seen before include "with all in chorus?" , "all agreed" , "All together in unison - males only" , "in complete agreement" , "arguably sexist in Unison" .)