Madison420 , 10 months ago

It’s an old pigeon French use, if you’re interested in that sort of thing it’s etymology.

Namely there are several warships named indefatigable.

www.etymonline.com/word/indefatigable

1580s (implied in indefatigably), from French indefatigable (15c.), from Latin indefatigabilis "that cannot be wearied," from in- “not” (see in- (1)) + defatigare "to tire out," from de- “utterly, down, away” (see de-) + fatigare "to weary" (see fatigue (n.)).