- The definition of indefatigable is a person or something that has tireless persistence.
Someone who keeps trying and trying to learn a skill and who never gives up is an example of a person who would be described as indefatigable.
Origin of indefatigableMiddle French indéfatigable ; from Classical Latin indefatigabilis ; from in-, not + defatigare, to tire out, weary: see de- and amp; fatigue
Origin of indefatigableObsolete French indéfatigable, from Latin indēfatīgābilis : in-, not; see in–1 + dēfatīgāre, to tire out (dē-, intensive pref.; see de– + fatīgāre, to weary).
(comparative more indefatigable, superlative most indefatigable)
- defatigable (much less common)