Preventer /(?)/

Pre·vent·er

Preventer

n.
  1. One who goes before; one who forestalls or anticipates another. [Obs.]
  2. One who prevents or obstructs; a hinderer; that which hinders; as, a preventer of evils or of disease.
  3. An auxiliary rope to strengthen a mast. (Naut.)

Phrases & Compounds
Preventer bolts
fixtures connected with preventers to reënforce other rigging.
Preventer stay
Same as Preventer, 3.