They've had their marching orders...是什么意思？

They've had their marching orders...

他们已经收到了辞退的通知。

ve

abbr. Venezuela 委内瑞拉；

例句
Conclusion The TCD abnormity of VE occurs mainly in intracervical artery system.
结论病毒性脑炎脑血流动力学异常改变以颈内动脉系统为主.

had

v. 有（ have的过去式和过去分词 ），（亲属关系中）接受，拿，买到；

例句
He claimed that his parents had abandoned him...
他声称父母遗弃了他。

their

pron. 他（她，它）们的，在提及性别不详的人时，用以代替 him 或 her；

例句
Their permissiveness toward their children reflects the wild abandon of their own lives.
他们对孩子的放任折射出他们自身生活的放浪形骸。

marching

v. （坚定地向某地）前进( march的现在分词 )，进军，进展，游行示威（或抗议）；

例句
The ice was not thick enough to bear the weight of marching men.
冰不够厚，承载不了行军队伍的重量。

orders

n. （基督教的）圣职，牧师职，命令( order的名词复数 )，秩序，（会议、议会等的）程序，次序；v. （医生）开（处方）( order的第三人称单数 )，订购，（上帝、命运等）注定，点（饭菜，饮料等）；

例句
The army refused to accept orders from the political leadership...
军队拒绝接受政界领导层下达的命令。