line of sight


Also called line of sighting. an imaginary straight line running through the aligned sights of a firearm, surveying equipment, etc.
Astronomy. an imaginary line from an observer to a celestial body, coincident with the path traveled by light rays receivedfrom the body.
Radio. a straight line connecting two points sufficiently high and near one another so that the line is entirely above the surface of the earth.
Ophthalmology. line of vision.



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Origin of line of sight

First recorded in 1550–60 Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2020

Example sentences from the Web for line of sight

  • There were other instruments in other line-of-sight positions, very far away.

    Operation Terror|William Fitzgerald Jenkins
  • I'm inclined like everybody else to consider perception on a line-of-sight basis instead of on a sort of all-around grasp.

    Highways in Hiding|George Oliver Smith
  • He started the fuel pumps winding up, and swung the ship to point normal to the line-of-sight to the jammer.

    Pushbutton War|Joseph P. Martino

British Dictionary definitions for line of sight

line of sight


the straight line along which an observer looks or a beam of radiation travels
ophthalmol another term for line of vision
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012