show (one's) mettle(redirected from show your mettle)
show (one's) mettle
To show that one has endurance and strength of character, or the necessary skills, abilities, or traits to succeed in something. You may be the youngest lawyer in the firm, but you certainly showed your mettle in that high-profile murder case. The new CEO showed her mettle when she completely restructured the dying mobile phone division into the powerhouse it is today.