Opens French one and holds (7)
I believe the answer is:
unlocks
'opens' is the definition.
(unlocking is a kind of opening)
'french one and holds' is the wordplay.
'french one' becomes 'un' ('one' in French).
'and' says to put letters next to each other.
'holds' becomes 'locks' (lock is a kind of hold).
'un'+'locks'='UNLOCKS'
(Other definitions for unlocks that I've seen before include "coil of hair, not black hair" , "Unfastens" , "Releases with a key" .)