Meaning of dumb sheave

dumb' sheave'

Pronunciation: [key]
— Naut. Naut.
  1. a block having no sheave or other part rolling with the movement of a line.
  2. a groove in a spar or other timber, through which a rope can slide.
Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease.