French heads holding a private conversation (4-1-4)
I believe the answer is:
tete-a-tete
'private conversation' is the definition.
(I've seen this before)
'french heads holding a' is the wordplay.
'french heads' becomes 'tete tete' ('tete' is 'head' in French).
'holding' indicates putting letters inside.
'tetetete' going around 'a' is 'TETE-A-TETE'.
(Other definitions for tete-a-tete that I've seen before include "Private conversation between two French people" , "One-to-one meeting" , "Private couple's conversation" , "Private conversation between two people as in France" , "Informal chat" .)