Indefatigable
/ˌɪndɪˈfætɪɡəbəl/
adjectiveC1
Definition
Indefatigable means not becoming tired even after a lot of effort or time. It describes a person or their spirit that continues working or trying without giving up, showing great energy and determination.
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See It in Action
Describing a person or their effort who never gets tired
- •She was an indefatigable worker, always finishing her tasks with energy.
- •His indefatigable spirit helped the team win the game.
- •The indefatigable volunteer worked all day without a break.
Used to describe continuous, tireless effort in any activity
- •The scientist showed indefatigable dedication to her research.
- •Despite many challenges, his indefatigable pursuit of justice never stopped.
Make It Stick
- ✓Think of "indefatigable" like "tireless" (A2 word), but even stronger—like having endless energy that never runs out.
- ✓Picture a runner who keeps going and going, never slowing down, no matter how long the race is.
- ✓It's the feeling when you want to keep doing something important, even if it is hard and long.
- ✓Sounds like "in-de-fat-i-ga-ble" → Imagine "in" meaning "not," and "fatigue" meaning "tired," so "not tired at all."
- ✓Think of superheroes or famous explorers who keep going without stopping, no matter the problems.
- ✓NOT like "tired" or "sleepy"—indefatigable people do not feel tired.
- ✓NOT like "lazy"—indefatigable means active and full of energy.
- ✓NOT like "restless" (unable to stay still because of nervousness)—indefatigable is about strong, steady effort, not nervous energy.
Try Other Words
- •Tireless: never getting tired (Use in everyday conversation for someone who works hard without stopping)
- •Persistent: continuing firmly without giving up (Use when focusing on not quitting, even if tired)
- •Energetic: full of energy (Use when describing lively and active behavior, not always about not getting tired)
- •Unflagging: never becoming weaker or less active (Use in formal writing for continuous effort)
Unboxing
- •Word parts: prefix "in-" (not) + root "defatigable" (able to be tired) → meaning "not able to be tired"
- •Etymology: From Latin "indefatigabilis," from "de-" (completely) + "fatigare" (to tire)
- •Historical development: Used since the 1600s to describe people who do not get tired or give up easily
- •Modern usage: Common in formal speech and writing to praise strong, continuous effort or energy
Reflect & Connect
•Can someone be indefatigable in all parts of life, or only in certain activities? Why?
•How does being indefatigable help people reach their goals, and can it ever be a problem?
Fill in the blanks
1.The athlete was indefatigable, so she kept training ___ even after many hours of practice.
2.His indefatigable attitude helped him ___ every obstacle in his path.
3.Unlike a tired person, an indefatigable worker does not ___ easily.
4.When the team faced problems, the coach’s indefatigable spirit ___ everyone to keep going.
5.People describe her as indefatigable because she works ___ without resting.
6.Indefatigable people often show ___ dedication that lasts a long time.
7.You might say someone is indefatigable if they never ___, even when things are very hard.