backsight

noun

1

surveying : a reading of the leveling rod in its unchanged position when the leveling instrument has been taken to a new position

2

surveying : a sight directed backward to a previous station

Word History

First Known Use

1847, in the meaning defined at sense 1

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