[verb]He signed the waiter to bring him another drink (= gave an order or information, or made a request, using hand and body movements). [T + object + to infinitive]He signed for/to the waiter to bring him another drink. [I]He signed to the waiter that he wanted another drink. [+ that clause]To sign is also to use sign language.
SIGN
Meaning of SIGN in English
Cambridge English vocab. Кембриджский английский словарь. 2012