adj. 25B6; adjective VIGOROUS, energetic, industrious, determined, enthusiastic, keen, zealous, spirited, dynamic, dogged, tenacious, persevering, stout, untiring, unwearying, indefatigable, unflagging.
lazy.
TIRELESS
Meaning of TIRELESS in English
Concise Oxford thesaurus English vocabulary. Краткий оксфордский словарь английского языка тезаурус. 2012