“Avoir la flemme” is a commonly used French expression that translates literally to “to have phlegm” and means “to be lazy”, “not feel like”, “can’t be asked” and “can’t be bothered”. La flemme translates to “laziness”.
Avoir la flemme
to be lazy to, can’t be bothered

Expression origin
The expression avoir la flemme dates back to the Middle Ages. At that time, doctors thought that certain body fluids had an impact on mood and behavior. Somebody with little “phlegm” was said to be full of energy.
Example sentences
Je devrais apprendre tous ces nouveaux verbes que le prof m’a donnés mais j’ai la flemme.
I should learn all these verbs that the teacher gave me but I can’t be bothered.
Avoir la flemme can also be followed by de + infinitive, meaing “to be too lazy to + verb”. Here’s an example:
J’ai la flemme de travailler aujourd’hui. Je reste sur le canapé devant la télévision.
I can’t be bothered to work today. I’ll stay on the sofa in front of the TV.

French expression | Lessons by David Issokson