noun
playing with hina dolls; Girl's Festival doll play
Refers to the traditional activity of setting up and playing with the ornamental dolls displayed for Hinamatsuri (March 3rd).
女の子たちは雛遊びを楽しんだ。
The girls enjoyed playing with the hina dolls.
雛祭り is the Doll's Festival itself, while 雛遊び is the act of playing with the dolls.
Compound of 雛 (hina, 'doll') and 遊び (asobi, 'play').