fail completely to produce the intended or expected effect
完全失败，完全未达到预期效果
his jokes fell flat.
他的笑话都没有达到预期效果。
fall over forwards
向前跌倒
as fast or as hard as possible
尽可能快；尽最大努力，竭尽全力
the whole team is working flat out to satisfy demand.
整个团队正竭尽全力来满足需求。
[as adj. flat-out]the album lacks the flat-out urgency of its predecessor.
这张专辑不像上一张那样迫在眉睫。
(informal, chiefly N. Amer.)without hesitation or reservation; unequivocally
(非正式，主北美)毅然地，果断地；毫无保留地；毫不含糊地
in those early days I'd just flat out vote against foreign aid.
开始的那几天我只会毫不含糊地投票反对外来援助。
[as adj. flat-out]flat-out perjury.
毋庸置疑的伪证。
lying completely stretched out, especially asleep or exhausted
（尤指熟睡或疲惫时）四肢摊开
she was lying flat out on her pink bath towel.
她舒展全身，躺在粉红色的浴巾上。
on level ground as opposed to uphill
在平地上
the car wouldn't go uphill or overtake on the flat.
这辆车既不会爬坡上坎，也不会平地超车。
(informal)used to indicate that one has reached a decision and will not be persuaded to change one's mind
(非正式)就这么简单（用来表示作了决定而且不会改弦更张）
he won't go into a home and that's flat.
他不愿成家，就这么简单。
(Austral./NZ)leave one's family home to live in a flat
(澳／新西兰)离家租公寓住
in my third year I left home and went flatting with David.
三年级的时候我离开家，和大卫合租了一套公寓。