take French leave
US /teɪk frɛnʧ liːv/
UK /teɪk frɛnʧ liːv/

1.
prendre la poudre d'escampette, filer à l'anglaise
to leave without permission or without telling anyone
:
•
He decided to take French leave from the meeting, much to his boss's annoyance.
Il a décidé de prendre la poudre d'escampette de la réunion, au grand dam de son patron.
•
The soldier was punished for taking French leave from his post.
Le soldat a été puni pour avoir déserté son poste.