English
indefatigability
Attested from the 1630s.
Formed from indefatigable + -ity
Latin fatīgō ‘to fatigue, tire or weary’
Latin dēfatīgō ‘to tire out’
Latin indēfatīgābilis ‘untiring’
English indefatigable
The story
Attested from the 1630s.
Today it means
noun The state of being indefatigable: tirelessness; persistence; stamina.
Language periods are conventional ranges, not dates for this word.
Etymograph / indefatigability