hardhead

noun8

1. •
   One who is practical or hardheaded.
2. •
   A brown diving duck, Aythya australis, native to Australia.
3. •
   Any of certain saltwater sciaenid (Sciaenidae) fishes.
4. •
   Mylopharodon conocephalus of fresh waters in California.
5. •
   Any of several weeds in or formerly classified in the genus Centaurea, especially Russian knapweed (Acroptilon repens).
6. •
   Residual ore that failed to melt during a smelting process.
7. •
   (historical) A Scottish billon coin circulated in the reigns of Mary and James VI.
8. •
   (no longer used) Clash or collision of heads in contest.

   • Both play at hardhead till they break their brains — 1687