(harder, hardest)

1. [only before noun] definite; based on information that can be proved
   确实的；确凿的◆Is there any hard evidence that the company is recovering?
   有确凿证据显示公司正在复苏吗？◆We think about 90% of the email is internal, but we have no hard figures.
   我们认为 90% 的电子邮件是内部邮件，但没有确切的数字。⨁hard evidence / facts / figures / numbers
   确凿的证据／事实／资料／数字

 ➡  soft ●drive/strike a hard ˈbargainto argue in an aggressive way to try to force sb to agree on the best possible price or arrangement
狠狠杀价●ˌhard and ˈfast (used especially after no, not, etc. 常用於 no、not 等之後) that cannot be changed in any circumstances
不得更改◆There are no hard and fast rules about this.
这件事没有甚麽硬性的规定。