take someone's name in vain
idiomPart ofvain
take someone's name in vain — idiom
1. To use a person's name in a way that shows a lack of respect, often in a joking
1.idiom
Definition
To use a person's name in a way that shows a lack of respect, often in a joking or critical manner.
Example
The children teased each other by taking the teacher's name in vain when she left the room.
My grandfather joked that the neighbours were taking his name in vain whenever they mentioned his old car.