Meaning

noun a dead shot

noun (nautical) a round hardwood disk with holes and a grooved perimeter used to tighten a shroud

originFrom dead + eye. See glossary of nautical terms of "deadrise" for usage of "dead" to describe a stationary object or spatial stability of an object relative to motion. See nautical definition of "eye" for usage referring to the foremost part of a ship's bow that aims its orientation. For biological eye stabilization during head and neck movement, see vestibulo-ocular reflex

Etymology from Wiktionary, CC BY-SA 3.0