NSW Opportunity Class
Indefatigable
adjective/in-dih-FAT-ih-guh-bul/
Never getting tired no matter how much effort is needed.
In contextThe indefatigable ants rebuilt the nest again and again.
Remember it
In- (not) plus 'fatigue' — someone you simply cannot fatigue or tire out.
Use it well
Use to admire tireless energy and effort that never seems to flag.