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
Enis	-	Bosnian
Caden	KAY-dən	English (Modern)
Zalman	-	Yiddish
Chinasa	-	Western African, Igbo
Sarpedon	-	Greek Mythology
Lita	-	English