be on (one's) mettle

To be determined to succeed and thus prove one's worth, often in a difficult or unpleasant situation. I know my employees think I'm too young to be their supervisor, so I have to be on my mettle every day at the office.

Common Names:

Name	Pronounced	Usage
Medhat	-	Arabic
Rosario	ro-SAH-ryo (Spanish), ro-ZAH-ryo (Italian)	Spanish, Italian
Crescencia	-	Spanish
Shahrukh	-	Urdu, Indian, Hindi
HadiİYe	-	Turkish
Mehdi	-	Persian