[ ˌɪndɪ'fatɪgəb(ə)l ]
■ adjective persisting tirelessly; unflagging.
Derivatives
indefatigability noun
indefatigably adverb
Origin
C17: from Fr., or from L. indefatigabilis , from in- 'not' + de- 'away, completely' + fatigare 'wear out'.
[ ˌɪndɪ'fatɪgəb(ə)l ]
■ adjective persisting tirelessly; unflagging.
Derivatives
indefatigability noun
indefatigably adverb
Origin
C17: from Fr., or from L. indefatigabilis , from in- 'not' + de- 'away, completely' + fatigare 'wear out'.
Concise Oxford English vocab. Сжатый оксфордский словарь английского языка. 2004