noun Date: 1847 a formal language employing a system of hand gestures for communication (as by the deaf), an unsystematic method of communicating chiefly by manual gestures used by people speaking different languages
SIGN LANGUAGE
Meaning of SIGN LANGUAGE in English
Merriam Webster. Explanatory English dictionary Merriam Webster. Толковый словарь английского языка Мерриам-Уэбстер. 2012