Definition of birthday girl in English:

birthday girl

noun

informal
  • A girl or woman whose birthday is being marked.

    • ‘However, on a special occasion like this, a little heavily accented chat might have worked wonders on the birthday girl.’
    • ‘The children are encouraged to get involved with the show and the birthday girl or boy gets a magic wand, a certificate and a magic show badge.’
    • ‘The birthday girl went for the rack of lamb.’
    • ‘As the birthday girl, I took first bite at the bait: a mix of seafood and steak or ‘surf and turf’ as the King's Staith restaurant called it.’
    • ‘The full-colour result was very impressive and the birthday girl was very pleased with it.’