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

The systems are among a number of other things the theater offers to help make performances more accessible, including shows with sign language interpretation, Spanish subtitles and sensory-friendly performances, Collins said. —Lisa Schencker, Chicago Tribune, 24 Jan. 2026

The discovery of language skills in great apes — various gorillas and chimps learned substantial vocabularies in sign language or symbols — and that of tool use across the animal kingdom have, over the years, chipped away at the idea that there is any single ingredient that makes humans unique. —Tom Chivers, semafor.com, 13 Jan. 2026

Think sign language for people who can hear. —Assistant Editor, Los Angeles Times, 12 Jan. 2026

Lucy and Erin sometimes communicate via sign language to avoid making a sound. —Bilge Ebiri, Vulture, 9 Jan. 2026

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