T?te-?-t?te (3-2-3)
I believe the answer is:
one-to-one
't?te-?-t?te' is the definition.
(I've seen this before)
This is all the clue.
(Other definitions for one-to-one that I've seen before include "T?te-?-t?te" , "meeting?" , "Corresponding uniquely, each to another" , "12:59" .)