Indefatigable
/ˌɪn.dɪˈfæt.ɪ.ɡə.bəl/noun
Having seemingly unlimited energy or persistence; incapable of becoming tired.
Did you know?The word combines Latin in- (“not”) with defatigare (“to weary completely”), creating a linguistic refusal to be worn down.
Etymological Timeline
Classical Latin
Latin
fatigare
“To tire, weary, or exhaust”
Classical Latin
Latin
defatigare
“To weary thoroughly or wear out completely”
Late Latin
Latin
indefatigabilis
“Not capable of being tired out”
16th Century
French
indefatigable
“Untiring; incapable of fatigue”
16th Century
English
indefatigable
“Untiring, persistent, or relentlessly energetic”
Modern English
English
indefatigable
“Continuing with great energy and determination without tiring”
Explore more surprising origins