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Synonyms

mettle

American  
[met-l] / ˈmɛt l /

noun

  1. courage and fortitude.

    a man of mettle.
    Synonyms:
    fiber, nerve, ardor, vigor, pluck, valor

  2. disposition or temperament.

    a man of fine mettle.

idioms

  1. on one's mettle, in the position of being incited to do one's best.

    The loss of the first round put him on his mettle to win the match.
mettle British  
/ ˈmɛtəl /

noun

  1. courage; spirit

  2. inherent character

  3. roused to putting forth one's best efforts

"Collins English Dictionary — Complete & Unabridged" 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Etymology

Origin of mettle

1575–85; spelling variant of metal, in metaphoric usages

Explanation

Mettle is the courage to carry on. If someone wants to "test your mettle," they want to see if you have the heart to follow through when the going gets tough. Having the mettle to do something means you have guts. In short, you're a pretty impressive person. If you have the intellectual mettle to enter a political debate, not only do you know a lot about politics, but you have the spunk to show it off. Metal and mettle were once used interchangeably meaning a solid material like gold and the "stuff a person is made of" — until everyone got confused and the words went their separate ways.

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Example Sentences

Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.

While that may be unfashionable in today’s world of prediction markets, cryptocurrencies, and highflying artificial-intelligence bets, Vanguard Wellington has long proven its mettle and is likely to keep doing so.

From Barron's • Apr. 3, 2026

Newcastle showed their mettle to see the game out, which felt timely before Wednesday's trip to the Nou Camp.

From BBC • Mar. 14, 2026

These Celtics have an underdog’s mettle, imbued by their eccentric head coach and jiu-jitsu enthusiast Joe Mazzulla.

From The Wall Street Journal • Mar. 2, 2026

Members no longer need to hold the floor and talk nonstop, testing not just the power of their argument but their physical mettle and bladder control.

From Los Angeles Times • Dec. 11, 2025

“Do not test my mettle, dastardly villain!” warned Major Puff.

From "The Very, Very Far North" by Dan Bar-el

Definitions and idiom definitions from Dictionary.com Unabridged, based on the Random House Unabridged Dictionary, © Random House, Inc. 2023

Idioms from The American Heritage® Idioms Dictionary copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.