noun
- A weedy perennial with tough wiry stems and purple flowers; native to Europe but widely naturalized.
- synonyms: lesser knapweed, black knapweed, Centaurea nigra
WordNet 3.0 © 2006 by Princeton University
| APA | WordNet. (2010). hardheads. Retrieved September 20, 2026, from http://smartdefine.org/hardheads/definitions/1284122 |
| Chicago | WordNet. 2010. "hardheads" http://smartdefine.org/hardheads/definitions/1284122 (accessed September 20, 2026). |
| Harvard | WordNet 2010, hardheads, Smart Define, viewed 20 September, 2026, <http://smartdefine.org/hardheads/definitions/1284122>. |
| MLA | WordNet. "hardheads" 23 October 2010. Web. 20 September 2026. <http://smartdefine.org/hardheads/definitions/1284122> |