WordReference Random House Unabridged Dictionary of American English © 2026
fly′ block′, [Mach., Naut.]
- Mechanical Engineering, Naval Terms(in a Spanish burton or the like) a block, supported by a runner, through which the hauling part of the fall is rove.
- Mechanical Engineering, Naval Termsany block that shifts with the movement of its tackle.
- 1835–45