Definition of persistent :
1. ( biology) retained; not shed; " persistent leaves remain attached past maturity"; " the persistent gills of fishes"
2. Inclined to persist; having staying qualities; tenacious of position or purpose.
3. Remaining beyond the period when parts of the same kind sometimes fall off or are absorbed; permanent; as, persistent teeth or gills; a persistent calyx; - opposed to deciduous, and caducous.
mulish, eternal, grim, pertinacious, long-standing, forbidding, lingering, intractable, retentive, saturnine, uninterrupted, opinionated, brutal, timeless, haunting, long, continue, glum, glowering, sullen, inflexible, importune, dour, unforgettable, ongoing, unforgiving, morose, unfailing, heady, unrelenting, around-the-clock, refractory, dark, recollective, unappeasable, round-the-clock, long-lasting, unconquerable, importunate, chronic, long-lived, perdurable, moody, contumacious, urgent, sour, old
resolute (part of speech: adjective)
hearty, committed, zealous, decisive, fearless, dogged, insistent, thorough, bold, steely, implacable, unshakeable, stubborn, ruthless, headstrong, reliable, inexorable, resolute, earnest, strong-willed, serious, faithful, diligent, iron-willed, relentless, willing, devoted, unflinching, tireless, valiant, dauntless, set, intent, true, unbending, spunky, unyielding, decided, resolved, bullheaded, steady, courageous, determined, strong-minded, tough, loyal, deliberate, staunch, firm, uncompromising, plucky, dedicated, stern
permanent (part of speech: adjective)
stable (part of speech: adjective)
tenacious (part of speech: adjective)
continuous (part of speech: adjective)
gapless, unchanging, ceaseless, repeated, repetitive, continuous, undeviating, robot-like, homogeneous, featureless, consecutive, unvarying, perennial, monotonous, endless, coherent, incessant, habitual, flat, connected, regular, consistent, continual, recurrent, unending, level, continuing, seamless, cyclical, uniform, un-intermittent, unbroken, unremitting, sequential, nonstop, even, invariable, straight, undying, monolithic
persevering (part of speech: adjective)
continued (part of speech: adjective)
- He would fain stretch out his arms to her, but he is perpetually tormented by the persistent question, " Whom does she resemble?" - "Erlach Court", Ossip Schubin.
- " Say at once you are glad to be rid of me," breaks he in bitterly, stung by her persistent coldness. - "Molly Bawn", Margaret Wolfe Hamilton.
- It was clear that a new era in the University's life was about to begin, but that persistent energy and determination would be required to guide the University through the night that still covered it. - "McGill and its Story, 1821-1921", Cyrus Macmillan.