untirable

Incapable of being tired; never tiring.

Japanese Meaning

疲れを知らない、決して疲れない

Her untirable enthusiasm kept the team going through the toughest nights.

彼女の疲れ知らずの熱意が、最も厳しい夜でもチームを支え続けた。

Sense（1）

Incapable of being tired; never tiring.

A most incomparable man, breathed, as it were,

To an untirable and continuate goodness […]

more untirable

（ comparative ）

most untirable

（ superlative ）