To make an effort greater than is required.竭盡全力：做比所需的更大的努力
英語四級真題
If you could move faster than light, your time would move backward.
出自-2011年6月聽力原文
英語六級真題
The reasoning behind this saying is that low oil prices discourage investment in new production capacity, eventually shifting the oil supply curve backward and bringing prices back up as existing oil fields—which can be tapped at relatively low marginal cost—are depleted.
出自-2017年6月閱讀原文
It is the season for some frantic last-minute math一across the country, employees of all stripes are counting backward in an attempt to figure out just how much paid time-off they have left in their reserves.
2017年12月六級真題（第三套）閱讀 Section C
The reasoning behind this saying is that low oil prices discourage investment in new production capacity, eventually shifting the oil supply curve backward and bringing prices back up as existing oil fields—which can be tapped at relatively low marginal c
2017年6月六級真題（第一套）閱讀 Section B
柯林斯高階英漢雙解學習詞典釋義
ADJ
向后的，往后的（一些人亦使用backwards)
A backward movement or look is in the direction that your back is facing. Some people use backwards for this meaning.