at its (或 someone's) worst

in the most unpleasant, unimpressive, or unattractive state of which someone or something is capable

在最坏的情况下（在某人最糟的时候）

nothing's working at the moment, so I suppose you've seen us at our worst.

那时一切都不在运转，因此我觉得你看到的是我们最糟的时候。

at worst (或 the worst)

in the most serious case

在最严重的情况下，在最坏的情况下

at worst the injury could mean months in hospital.

在最坏的情况下，伤员得在医院躺上几个月。

be one's own worst enemy

at worst the injury could mean months in hospital.

在最坏的情况下，伤员得在医院躺上几个月。

do one's worst

do as much damage as one can (often used to express defiance in the face of threats)

［挑战用语］有什么手段尽管使出来

let them do their worst—he would never surrender.

让他们有什么手段尽管使出来吧——他永不投降。

get (或 have) the worst of it

be in the least advantageous or successful position; suffer the most

遭到失败；处于最不利的境地；大吃苦头

if the worst comes to the worst

if the most serious or difficult circumstances arise

如果事情坏到无可再坏，如果最坏的事发生；到一筹莫展的时候

at (the) worst

Under the most negative circumstances, estimation, or interpretation

在最坏的形式下：在最恶劣的环境，在最保守的估计下，在最不利的解释下

At worst, the storm will make us postpone the trip.

最坏的估计是暴风雨会使我们推迟行程

get the worst of it 或 have the worst of it

To suffer a defeat or disadvantage.

遭受失败或损失

if (the) worst comes to (the) worst

If the very worst thing happens.

如果最坏的事发生

in the worst way【非正式用语】

Very much; a great deal

非常地；十分地

wanted to be elected in the worst way.

极想当选