Sign language

Language that uses manual communication and body language to convey meaning

Sign languages (also known as signed languages) are languages that use the visual-manual modality to convey meaning rather than spoken words. They are expressed through manual articulation in combination with non-manual markers, and are full-fledged natural languages with their own grammar and lexicon. Sign languages are not universal and are usually not mutually intelligible, although there are similarities among different sign languages.

From Wikipedia, under CC BY-SA. More on occurri.