Take French Leave

First Example:
Taichi: What are you doing home at noon? Shouldn’t you be at work?
Michael: I didn’t feel like going to work today, so I decided to stay home and do nothing. I get paid
anyway.
Taichi: So you’re taking a French leave? Nice, but I don’t have paid days like you, so I can’t afford that.
Michael: That’s too bad, I’m going to enjoy any time off I can.

Second Example:
Supervisor: Good morning Don. How can I help you?
Don: I don’t really feel like working today.
Supervisor: Are you feeling okay? Are you sick?
Don: Not really. I just want to take the day off.
Supervisor: I can’t get you covered for the day for a French leave. You could have given me a heads up.
We have a lot of work to cover. We need you.
Don: You can’t force me to be here.

Meaning: To take a “French leave” means to take a break from work without asking for permission.

https://languagesystems.edu/