Hilaira (or Hiläeira) was the daughter of Leucippus. She was engaged to marry her uncle Lynceus but was abducted by Castor before she could marry him. Both she and her twin sister Phoebe (jointly known as the Leucippides) have 'shining' names that evoke the moon: hilaros (which was actually a by-name of the moon) means 'joyful', in turn linked to hilaos, 'gracious', 'cheerful' (and English 'hilarious').