Sign up for our Newsletter. Get the latest tutorials, inspiration and special offers from Mettle. Name: Email Address: SUBMIT. Definition of mettle. 1a : vigor and strength of spirit or temperament (see temperament sense 1a) a girl of … mettle who lost a baby brother to leukemia— Bill Zehme. b : staying quality : stamina equipment that proved its mettle proved his mettle in battle. Mettle definition, courage and fortitude: a man of mettle. 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. Etymology edit Originally a variant of metal. Pronunciation edit (UK, US) IPA: / ˈmɛt.l̩/; Rhymes: -ɛtəl · Homophones: metal, medal, meddle (in accents. Definition of mettle - a person's ability to cope well with difficulties; spirit and resilience. Synonyms for mettle at Thesaurus.com with free online thesaurus, antonyms, and definitions. Find descriptive alternatives for mettle. Define mettle. mettle synonyms, mettle pronunciation, mettle translation, English dictionary definition of mettle. n. The ability to meet a challenge or persevere. What's the meaning and origin of the phrase 'Show your mettle'. Mettle is known for innovation in the creation of specialised financial solutions. With clients ranging from international corporates to small and medium.