the belle of the ball (=the most beautiful girl at a dance or party) 舞会之花,舞会上最美的女子
Examples from the Corpus
belle• Her streakyblonde hair and skimpybikini were those of a nineteen-year-old beachbelle.• a Southernbelle• Sarah Stewart is a real Southern belle from Jackson, Mississippi, with long blonde hair and a magnoliadrawl.• Among the belles in that house Susan went relatively unnoticed, and could escape the dancing when she chose.
the belle of the ball• Caroline was the belle of the ball in her silver and white evening gown.
Originbelle
(1600-1700)French from the feminine form of beau; → BEAU