1 familiar (to sb) well known to you; often seen or heard and therefore easy to recognize 为某人所熟悉；熟悉的: to look/sound familiar 看╱听上去很熟悉Chinese music isn't very familiar to people in Europe. 欧洲人不大熟悉中国音乐。It was a relief to see a familiar face in the crowd. 在人群中看见一张熟悉的面孔，令人松一口气。

2 familiar with sth having a good knowledge of sth 熟悉；通晓: People in Europe aren't very familiar with Chinese music. 欧洲人不大熟悉中国音乐。 [OPP] for senses 1 and 2 unfamiliar 第1及2义的反义词皆为unfamiliar

3 familiar (with sb) (used about a person's behaviour) too friendly and informal （指行为）过分亲昵的，过分随便的: I was annoyed by the waiter's familiar behaviour. 那位服务员对顾客太随便，叫我很反感。