line of sight

noun phrase

Definition of line of sight

1 : a line from an observer's eye to a distant point
2 : the line between two points specifically : the straight path between a transmitting antenna (as for radio or television signals) and a receiving antenna when unobstructed by the horizon

First Known Use of line of sight

1559, in the meaning defined at sense 1

Keep scrolling for more

Learn More about line of sight

Time Traveler for line of sight

Time Traveler

The first known use of line of sight was in 1559

See more words from the same year

Statistics for line of sight

Cite this Entry

“Line of sight.” Dictionary, Merriam-Webster, Accessed 11 Jul. 2020.

Keep scrolling for more

More Definitions for line of sight

line of sight


Medical Definition of line of sight

1 : a line from an observer's eye to a distant point

More from Merriam-Webster on line of sight

Rhyming Dictionary: Words that rhyme with line of sight

Comments on line of sight

What made you want to look up line of sight? Please tell us where you read or heard it (including the quote, if possible).


See Definitions and Examples »

Get Word of the Day daily email!

Test Your Vocabulary

Words for Summer: A Quiz

  • a closeup of a sunflower
  • Which of the following words means “of or relating to summer”?
Spell It

Can you spell these 10 commonly misspelled words?

Add Diction

Test Your Knowledge - and learn some interesting things along the way.

Love words? Need even more definitions?

Subscribe to America's largest dictionary and get thousands more definitions and advanced search—ad free!