rock bottom star1 (alsorock-bottom)

• 1.  

  N-UNCOUNT（不可数名词） If something has reached rock bottom, it is at such a low level that it cannot go any lower. 最低谷

  例：

  Morale in the armed forces was at rock bottom.

  那时军队的士气处在最低谷。

• 2.  

  ADJ（形容词） A rock-bottom price or level is a very low one, mainly in advertisements. 底线的 (价格、水平)[表赞许]

  例：

  What they do offer is a good product at a rock-bottom price.

  他们真正提供的是一种以价格在底线的优质产品。