1. 护送者;护卫者；押送者
    An escort is a person who travels with someone in order to protect or guard them.

    e.g. He arrived with a police escort shortly before half past nine.
           快到9点半的时候，他在一名警察的护送下到达了。

2. （陪同异性的）社交聚会陪伴者；（有时指）有偿社交伴侣
    An escort is a person who accompanies another person of the opposite sex to a social event. Sometimes people are paid to be escorts.

    e.g. My sister needed an escort for a company dinner.
           我妹妹需要一个陪她参加公司晚宴的男伴。

3. 陪同；护送
    If you escort someone somewhere, you accompany them there, usually in order to make sure that they leave a place or get to their destination.

    e.g. I escorted him to the door...
           我陪他走到门口。
    e.g. The vessel was escorted to an undisclosed port.
           那艘轮船在护航下前往一个秘密港口。