lazy jack

noun

1

: a device that compensates for expansion and contraction (as in a pipe line) consisting of two linked bell cranks pivoted at the vertices of their complementary angles

2

: an often forked line reaching from the masthead or the topping lift on each side of a fore-and-aft sail to about the middle of the boom to confine the sail when it is lowered

—usually used in plural

The Ultimate Dictionary Awaits

Expand your vocabulary and dive deeper into language with Merriam-Webster Unabridged.

1. Expanded definitions
2. Detailed etymologies
3. Advanced search tools
4. All ad-free

Discover what makes Merriam-Webster Unabridged the essential choice for true word lovers.

Start Your Free Trial Now