Fly block

Related to Fly block: black fly
(Naut.) a pulley whose position shifts to suit the working of the tackle with which it is connected; - used in the hoisting tackle of yards.

See also: Fly

Webster's Revised Unabridged Dictionary, published 1913 by G. & C. Merriam Co.
References in periodicals archive ?
Photos in the Shoo Fly Block instructions and diagrams in the Bear's Paw Variation Block instructions demonstrate a basic, fast technique useful when you need multiple pieced squares of the same fabric combination.