a young girl who walks in front of the bride (= the woman getting married) at a wedding (= a marriage ceremony) carrying flowers and sometimes dropping petals on the ground

My 4-year-old niece was a flower girl at my wedding. 我4岁的侄女是我婚礼上的花童。

a girl or woman who sells flowers, especially in the street

The film tells the story of a professor and a flower girl. 这部电影讲述了一位教授和一位卖花女的故事。