from Wiktionary, Creative Commons Attribution/Share-Alike License
- n. The rear sight of a firearm.
- n. A measurement or reading taken back towards a point of known elevation, used to calculate the height of the theodolite.
- n. A measurement of a previously shot point, used to set the angle to zero when occupying a new position.
- v. To shoot a backsight.
from the GNU version of the Collaborative International Dictionary of English
- n. The reading of the leveling staff in its unchanged position when the leveling instrument has been taken to a new position; a sight directed backwards to a station previously occupied. Cf. foresight, n., 3.
from The Century Dictionary and Cyclopedia
- n. In surveying, the reading of a leveling-rod, taken when looking back to a station which has been passed. All other readings are called foresights.
- n. The rear sight of a gun.
From the back + sight (Wiktionary)