嘴不严 Traditional form: 嘴不嚴 Pinyin (reading): zuǐbùyán Definitions: to have a loose tongue Characters: 嘴 - mouth, lips 不 - no, not, un-; negative prefix 严 - strict, rigorous, rigid; stern Traditional characters: 嘴 - mouth, lips 不 - no, not, un-; negative prefix 嚴 - strict, rigorous, rigid; stern