One of several natural languages, typically used by the deaf, in which words and phrases are represented by hand shapes, motions, positions, and facial expressions.
The sign language (sense 1) that is used locally or that is mistakenly believed to be the only one.
Sign languages (sense 1) considered collectively.
(countable or uncountable) Communication through gestures used when speech is impossible, for example, between monks under a vow of silence or people speaking different languages.