backsight
|back-sight|
/ˈbæk.saɪt/
a sighting taken backward to a known point
Etymology
'backsight' originates from English, specifically the compound of the words 'back' and 'sight', where 'back' comes from Old English 'bæc' meaning 'rear' and 'sight' comes from Old English 'siht' meaning 'the act of seeing or a view.'
'backsight' formed as a compound in modern English (back + sight) and came into technical use in surveying terminology in the 18th–19th centuries to denote a sight taken to a known (rear) point.
Initially it simply meant 'a view to the back/rear', but over time it became a technical surveying term meaning 'a level reading taken on a point of known elevation.'
Meanings by Part of Speech
Noun 1
a surveying reading taken on a point of known elevation (a benchmark or previously established point) used to determine the instrument height or to establish heights of other points; the opposite of a 'foresight.'
The surveyor took a backsight on the benchmark before beginning the level run.
Synonyms
Antonyms
Last updated: 2025/12/27 06:02