What is full of spirit; possessing constitutional ardor; fiery; as, a mettlesome horse. -- Met"tle*some*ly, adv. -- Met"tle*some*ness, n called?

mettlesome — Full of spirit; possessing constitutional ardor; fiery; as, a mettlesome horse. -- Met"tle*some*ly, adv. -- Met"tle*some*ness, n. (Webster's 1913.)

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