Phrasal verb WAIT UP

WAIT UP

1. To wait up is to stay awake and not go to bed because you are waiting for someone. Examples of use:

1. I’ll be home late tonight. Don’t wait up for me.
2. What time did you get home last night? Your mother and I waited up for you until 2am.

2.Wait up! is something you say to someone if you want them to stop and wait for you.

Mainly American English

Examples of use:

1. Wait up! I’ll get my coat and come with you.
2. Wait up! I need to talk to you before you go.
3. Wait up! You’ve forgotten your briefcase.