line of sight

American  

[lahyn uhv sahyt] / ˈlaɪn əv ˈsaɪt /

noun

1. Also called line of sighting.  an imaginary straight line running through the aligned sights of a firearm, surveying equipment, etc.

2. Astronomy. an imaginary line from an observer to a celestial body, coincident with the path traveled by light rays receivedfrom the body.

3. 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.

4. Ophthalmology. line of vision.

5. sightline.

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line of sight British  

noun

1. the straight line along which an observer looks or a beam of radiation travels

2. ophthalmol another term for line of vision

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Etymology

Origin of line of sight

First recorded in 1550–60

Example Sentences

“Even as we expect industry supply to improve gradually in 2028, we currently do not have line of sight as to when memory supply will be able to catch up with increasing demand.”

From Barron's • Jun. 26, 2026

The sector is in a much better position and there is more line of sight to quantum really becoming a reality, a senior Commerce Department official said.

From The Wall Street Journal • May 21, 2026

For commercial drones to become an everyday reality, operators need to be able to fly them beyond the visual line of sight, or BVLOS.

From BBC • May 6, 2026

Always in each other’s line of sight, always negotiating space that didn’t exist.

From Los Angeles Times • Apr. 3, 2026

If your enemy’s Artifact is within your line of sight, then using this power-up will automatically teleport that Artifact straight into your hands, instantly winning your team the game.

From "Warcross" by Marie Lu