hapax legomenon (noun)

1. As a sign of their commitment to each other, the couple exchanged personalized hapax legomenons during their wedding ceremony.

2. The cartoon characters often use hapax legomenons to add humor and catchphrases to the show.

3. In ancient mythology, gods and goddesses were known to have their own unique hapax legomenons to invoke their powers.

4. The superhero's signature move was to recite a hapax legomenon before defeating the villain.