Actress unknown to faceless man (7)
I believe the answer is:
lorenzo
'man' is the definition.
'actress unknown to faceless' is the wordplay.
'actress' becomes 'Loren' (Sophia Loren).
'unknown' becomes 'z' (represents an unknown value in algebra).
'faceless' means to remove the first letter.
'to' with its first letter removed is 'o'.
'loren'+'z'+'o'='LORENZO'
(Other definitions for lorenzo that I've seen before include "Florentine ruler, -- de' Medici, the Magnificent" , "Venetian lover" , "He loves Jessica (M. of V.)" , "lover of Jessica" , "Italian" .)