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

Backed by strong ties to deaf communities, Signapse targets a $500 million serviceable market, expanding beyond BSL and ASL toward 300+ sign languages. —Callum McLennan, Variety, 26 Sep. 2025

Though historians have called for further research before making claims, the proposal of a script rooted in sign language might open the chance to explore a new way of deciphering Mayan art and show the ancient civilization to be even more sophisticated and efficient than scholars even knew. —Maria Mocerino, Interesting Engineering, 21 Sep. 2025

In a statement, the DHS spokesperson said ICE staff provided Diaz Santana with a communications board and an American sign language interpreter. —Armando Garcia, ABC News, 18 Sep. 2025

Watching the actors sign language through glee, heartache, torment and even betrayal makes for some stunning scene work. —Lily Ford, HollywoodReporter, 9 Sep. 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