skeg

noun7

1. •
   A fin-like structure to the rear of the keel of a vessel that supports the rudder and protects a propeller.
2. •
   A similar construction on a boat that acts as a keel.
3. •
   A fin that serves to stabilize a surfboard.
4. •
   (Australia, slang) A surfer; a person who leads a surfing lifestyle.
5. •
   (Northern-England) A look or glance.
6. •
   (no longer used) A sort of wild plum (Prunus spinosa or Prunus domestica subsp. insititia (syn. Prunus institia)).

   • Some take them for Damascen plums, or rather for Bullois, Skegs, or such like wilde Plums. — 1601
7. •
   (no longer used) A kind of oat.

   • SKEGS. A kind of oat, sometimes cultivated as a crop in Nottinghamshire. It is the Avena stipiformis of Linnaeus. — 1842