tireless, irrepressible, indomitable, redoubtable, untiring, dauntless, unflagging, doughty, fearless, tenacious, peerless, intrepid, assiduous, nonpareil, inveterate, ardent, implacable, voluble, peripatetic, wily, stakhanovite, admirable, unflappable, unstinting, stalwart, genial, inimitable, unfailing, unwavering, inexhaustible, garrulous, relentless, imperturbable, ageless, unswerving, industrious, enterprising, unyielding, pugnacious, irascible, effervescent, undying, steely, ceaseless, unerring, prodigious, resourceful, quixotic, unabashed, adroit, feisty, uncomplaining, imperious, octogenarian, fervent, bon vivant, farseeing, energetic, impish, charismatic, erudite, eloquent, incorrigible, affable, pertinacious, uncompromising, sprightly, canny, amiable, workaholic, dutiful, unfaltering, unassuming, crusading, oleaginous, unrelenting, astute, stouthearted, iconoclastic, unflinching, estimable, protean, resolute, fastidious, perseverant, selfless, cantankerous, avuncular, ferocious, unbending, loquacious, plucky, impeccable, ebullient, valiant, crackerjack, spry, zealous, saintly, grand inquisitor, steadfast, undiminished, unwearied, persevering, diligent, unwearying, conscientious, unremitting, sedulous, painstaking, unremitted, earnest, sacrificing, unceasing, able

ball of fire, dogging, fireball, human dynamo, indefatigably, inexhaustibly, persisting, powerhouse, tirelessly