rear-guard

基本解释

Recalling the care his quarry had displayed in defeating the crypt traps, he ordered a three-elf rear guard to follow behind.
再次提醒那些被追捕者擊敗了陷阱之後，加拉隆命令一個由三名精霛組成的後衛小隊跟隨。
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A little behind them, there sat on the trunk of a cannon, Nesvitsky, who had been despatched by the commander-in-chief to the rear-guard.
在他們背後幾步路遠的地方，由縂司令派往後衛部隊的涅斯維茨基正坐在砲架尾部。
At ten o'clock in the morning of the 2nd of September the only troops left in the Dorogomilov suburbs were the regiments of the rear-guard, and the crush was over.
到九月二日上午十點鍾爲止，在多羅戈米洛夫郊野衹賸下後衛部隊了。

You and your lawyers want to thrash this out, case by case, fighting a trench-warfare, rear-guard action?
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Even now it is waging a rear-guard action to undo the easing that the FASB promulgated in April.
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The judge's clumsy move is a rear-guard action against a basic freedom.
FORBES: Fact and Comment

In a battle, the rearguard is a group of soldiers who protect the back part of an army, especially when the army is leaving the battle.
If someone is fighting a rearguard action or mounting a rearguard action, they are trying very hard to prevent something from happening, even though it is probably too late for them to succeed.