sign language
noun /ˈsaɪn læŋɡwɪdʒ/
  /ˈsaɪn læŋɡwɪdʒ/
[uncountable, countable]- a system of communicating using hand movements rather than spoken words, as used by people who cannot hear
手势语 - They communicate in sign language.
他们用手语交流。  
- Not all deaf people use sign language.
并非所有耳聋的人都使用手语。  - I got by with broken Chinese and sign language.
我用蹩脚的汉语加上比比画画勉强应付。  
 - They communicate in sign language.