take French leave /frentʃ/

　　不辞而别，擅自行动，擅离职守

　　This phrase means thatsomeone leaveswithout saying goodbye to others， or doessomething without the consent of othersorthe party concerned。

　　这个短语指的是某人没有和别人告别就离开了，或指没有经过有关方或他人的同意，就擅自做了某事。

　　Why did you take French leaveat Tom‘s birthday party last night？

　　你昨晚为什么在Tom的生日派对上不辞而别了呢？

　　He seemed to have something urgentto deal with， so he tookFrench leaveduring the meeting。

　　他好像有什么急事，所以才会在开会期间没说一声就走了。