adj · 4 senses · updated from the 2026-07-25 local source snapshot
Definitions and examples are grouped by meaning. Pronunciation, history, word forms, translations, descendants, synonyms, antonyms, derived terms, and related words appear whenever the source provides them.
Sound
Pronunciation
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CMU ARPABET:T AY1 ER0 L AH0 S
Digits mark lexical stress: 1 primary, 2 secondary, 0 unstressed.
1
adj
Meaning 1
Indefatigable, untiring and not yielding to fatigue
Definition source: English Wiktionary via Wiktextract
Usage: not-comparable
No example sentence was provided for this meaning.
Meaning relationships
Synonyms: none provided
Antonyms: none provided
2
adj
Meaning 2
Without a tire (wheel covering); tyreless.
Definition source: English Wiktionary via Wiktextract
Usage: US, not-comparable
No example sentence was provided for this meaning.
Meaning relationships
Synonyms: none provided
Antonyms: none provided
3
adjective satellite
Meaning 3
characterized by hard work and perseverance
Definition source: Princeton WordNet 3.0
No example sentence was provided for this meaning.
Meaning relationships
Synonyms: hardworking, industrious, untiring
Antonyms: none provided
4
adjective satellite
Meaning 4
showing sustained enthusiastic action with unflagging vitality
Definition source: Princeton WordNet 3.0
Examples
an indefatigable advocate of equal rights
a tireless worker
unflagging pursuit of excellence
Meaning relationships
Synonyms: indefatigable, unflagging, unwearying
Antonyms: none provided
History
Etymology
Etymology tree English tire Proto-Indo-European *lewh1- Proto-Indo-European *lewHs-der. Proto-Germanic *leusaną Proto-Germanic *lausaz Proto-Germanic *-lausaz Proto-West Germanic *-laus Old English -lēas Middle English -les English -less English tireless From tire (“to become sleepy or weary”) + -less.
Etymology tree English tire Proto-Indo-European *lewh1- Proto-Indo-European *lewHs-der. Proto-Germanic *leusaną Proto-Germanic *lausaz Proto-Germanic *-lausaz Proto-West Germanic *-laus Old English -lēas Middle English -les English -less English tireless From tire + -less.
Across languages
Translations
32 source translations are retained for this English entry.
Armenian:
անդուլ
(andul)
— indefatigable
Azerbaijani:
yorulmaz
— indefatigable
Bulgarian:
неуморен
(neumoren)
— indefatigable
Catalan:
incansable
— indefatigable
Chinese Mandarin:
不倦
(bùjuàn)
— indefatigable
Chinese Mandarin:
不知疲倦的
(bùzhī píjuàn de)
— indefatigable
Dutch:
onvermoeibaar
— indefatigable
Esperanto:
nelacigebla
— indefatigable
Finnish:
väsymätön
— indefatigable
Finnish:
uupumaton
— indefatigable
French:
inlassable
— indefatigable
Galician:
incansable
— indefatigable
Galician:
incansábel
— indefatigable
German:
unermüdlich
— indefatigable
Greek:
ακούραστος
(akoúrastos)
— indefatigable
Ancient Greek:
ἀκάματος
(akámatos)
— indefatigable
Italian:
instancabile
— indefatigable
Japanese:
疲れを知らない
(tsukare o shiranai)
— indefatigable