From The Collaborative International Dictionary of English v.0.48 [gcide]:
D'ebutant \D['e]`bu`tant"\, n.; fem. D'ebutante
\D['e]`bu`tante"\ [F., p. pr. of d['e]buter to have the first
throw, to make one's d['e]but. See {D['e]but}.]
A person who makes his (or her) first appearance before the
public.
[1913 Webster]
From The Collaborative International Dictionary of English v.0.48 [gcide]:
D'ebutante \D['e]`bu`tante"\, fem. n.
A young woman making her first appearance in society,
especially one who is one of the honorees at a debutante
cotillion. See cotillion[4].
[PJC]
From WordNet (r) 3.0 (2006) [wn]:
debutante
n 1: a young woman making her debut into society [syn:
debutante, deb]