mettle

He pioneered a style whereby callers had to be on their mettle because he was known to treat them in the same way he would treat a politician.

And Su will need to prove her mettle in a less familiar set of roles: as a saleswoman, dealmaker and lobbyist.

Now comes the hardest bit - the biggest test of their mettle to move another step closer to the greatest dream of them all.

His executive mettle was challenged when, during the 9/11 attacks, he found himself in charge at the White House while the president was traveling.

I knew part of me desperately wanted a chance to prove my mettle.