Quantcast
Merriam-Webster Logo
  • Dictionary
  • Thesaurus
  • Scrabble
  • Spanish Central
  • Learner's Dictionary

indefatigable

play
adjective in·de·fat·i·ga·ble \ˌin-di-ˈfa-ti-gə-bəl\

Simple Definition of indefatigable

  • : able to work or continue for a very long time without becoming tired

Source: Merriam-Webster's Learner's Dictionary

Full Definition of indefatigable

  1. :  incapable of being fatigued :  untiring <an indefatigable worker>

indefatigability

play \-ˌfa-ti-gə-ˈbi-lə-tē\ noun

indefatigableness

play \-ˈfa-ti-gə-bəl-nəs\ noun

indefatigably

play \-blē\ adverb

Examples of indefatigable in a sentence

  1. a person of indefatigable patience

  2. <an indefatigable laborer who can work from sunrise to sunset>



Origin and Etymology of indefatigable

Middle French, from Latin indefatigabilis, from in- + defatigare to fatigue, from de- + fatigare to fatigue


First Known Use: 1608



Seen and Heard

What made you want to look up indefatigable? Please tell us where you read or heard it (including the quote, if possible).

WORD OF THE DAY

to destroy or remove completely

Get Word of the Day daily email!

WORD GAMES

Take a 3-minute break and test your skills!

two-chairs-on-a-pier-by-the-ocean-in-summer

Which of the following words means “of or relating to summer”?

estival hiemal brumal vernal
Name That Thing

Test your visual vocabulary with our 10-question challenge!

TAKE THE QUIZ
SCRABBLE® Sprint

Test Your Knowledge - and learn some interesting things along the way.

TAKE THE QUIZ