Princeton's WordNet

1. girl, miss, missy, young lady, young woman, fille(noun)

   a young woman

   Synonyms:
   lady friend, missy, fille, miss, young woman, young lady, girl, female child, girlfriend, daughter, little girl, misfire

   Antonyms:
   boy, son, male child

2. female child, girl, little girl(noun)

   a youthful female person

   Synonyms:
   lady friend, missy, little girl, miss, fille, young woman, young lady, girl, female child, girlfriend, daughter

   Antonyms:
   boy, son, male child

3. daughter, girl(noun)

   a female human offspring

   Synonyms:
   lady friend, missy, fille, miss, young woman, young lady, girl, female child, girlfriend, daughter, little girl

   Antonyms:
   boy, male child, son

4. girlfriend, girl, lady friend(noun)

   a girl or young woman with whom a man is romantically involved

   Synonyms:
   lady friend, missy, fille, miss, young woman, young lady, girl, female child, girlfriend, daughter, little girl

   Antonyms:
   male child, son, boy

5. girl(noun)

   a friendly informal reference to a grown woman

   Synonyms:
   lady friend, missy, fille, miss, young woman, young lady, female child, girlfriend, daughter, little girl

   Antonyms:
   boy, son, male child