1 quality of endurance or courage, esp in people or horses 忍耐力, 勇气（尤指人或马的）
*a man of mettle 有勇气的人
* test sb's mettle 考验某人的耐力
* She showed her mettle by winning in spite of her handicap. 那匹雌马尽管增加了负重而仍能获胜, 可见很有耐力.
2 (idm 习语) be on one's `mettle; put sb on his `mettle be encouraged or forced to do one's best; encourage or force sb to do his best 奋发; 激励某人尽最大努力
*You'll be on your mettle during the training period. 你要在训练期间尽最大努力.
* The next race will put him on his mettle. 下次赛跑他就要全力以赴了.
[Date: 1500-1600; Origin: metal]
courage and determination to do something even when it is very difficult
test/show/prove your mettle
a crisis which will test the prime minister's mettle
on your mettle
BrE if you are on your mettle, you are ready to try as hard as possible because your abilities are being tested
We'll have to be on our mettle from the start.
keep/put sb on their mettle
This was just his way of keeping me on my mettle.