mid-15c., "lacking form; not in accordance with the rules of formal logic," from in- (1) "not, opposite of" + formal. Meaning "irregular, unofficial" is from c. 1600. Sense of "done without ceremony" is from 1828. Related: Informally.
实用例句
1. Council members are due to have informal discussions later on today.
委员会成员定于今日晚些时候进行非正式讨论。来自柯林斯例句
2. The two leaders will retire to Camp David for informal discussions.
两位领导人将到戴维营进行非正式讨论。来自柯林斯例句
3. Our aim was that these meetings be unstructured and informal.
我们的目的是，这些会议不事先进行精心组织，要随意一些。来自柯林斯例句
4. I would like it to be an informal occasion.
我希望把它办得不那么正式。来自柯林斯例句
5. His friend was less good-looking, but a lot more informal and relaxed.
