sign language

noun

1

: any of various formal languages employing a system of hand gestures and their placement relative to the upper body, facial expressions, body postures, and finger spelling especially for communication by and with deaf people

But true sign languages are in fact complete in themselves: their syntax, grammar, and semantics are complete, but they have a different character from that of any spoken or written language.

—Oliver Sacks

Sign language relies mainly on the signer's hand, but facial expressions and body movements are also important.

—Mark Prigg

2

: an unsystematic method of communicating chiefly by manual gestures (as by people speaking different languages)

I decided to cadge a lift from a Lebanese who only spoke Arabic, so we had to converse in sign language.

—Robert Fox

Examples of sign language in a Sentence

Recent Examples on the Web

This can mean creating best conditions for the neurodiverse, developing sign language that helps even babies learn about their world, and building entire educational systems abroad. —Alan Schwarz, Forbes.com, 17 June 2025

Isabela Merced told my colleague Kate Aurthur that during the subway sequence in Episode 4, you guys created a secret sign language with each other. —Adam B. Vary, Variety, 26 May 2025

There is a great video of Kim and her husband sandwiched together, front to back, facing the camera, in which one makes sign language and the other augments the signs with eyebrow movements, facial expressions, and changes of posture. —Jerry Saltz, Vulture, 14 Feb. 2025

There were sign language interpreters and wheelchair ramps. —Yejin Gim, Christian Science Monitor, 2 June 2025

Word History

First Known Use

1824, in the meaning defined at sense 1

Rhymes for sign language

• interlanguage
• metalanguage

Kids Definition

sign language

noun

1

: a formal language using a system of hand movements for communication (as by the deaf)

2

: a way of communicating mainly by hand and arm movements as often used by people speaking different languages

Medical Definition

sign language

noun

: any of various formal languages employing a system of hand gestures and their placement relative to the upper body, facial expressions, body postures, and finger spelling especially for communication by and with deaf people