thistledown n : pappus of a thistle consisting of silky featherlike hairs attached to the seedlike fruit of a thistle
- The soft feathery material which protects the fruiting part of a thistle.
- One of the servers in which the Massively Multi-player Online Role Playing Game Asheron's Call takes place, with characters you create, set in the fictional land of Dereth.
- The name the giant extrasolar asteroid/starship which serves as a venue for some of the action in science fiction author Greg Bear's EON series (Eon, Eternity, Legacy).
- The name of a fairie, a character in the book Flower Fables written by Louisa May Alcott.
- Thistledown (racecourse), a thoroughbred racing track in North Randall, Ohio, near Cleveland.