Synonyms and related words :
acute, assertive, assiduous, burning, cajoling, clamant, clamorous, coaxing, compelling, constant, continuing, critical, crucial, crying, demanding, determined, diligent, dire, dogged, draining, dunning, emphatic, enduring, exacting, exigent, exorbitant, extortionate, faithful, firm, forceful, grasping, high-pressure, high-priority, immutable, imperative, imperious, importunate, inalterable, indefatigable, indomitable, industrious, inexorable, instant, invincible, lasting, loud, loyal, nagging, never-tiring, obstinate, obtrusive, patient, patient as Job, permanent, perseverant, persevering, persistent, persisting, pertinacious, pestering, pivotal, plaguing, plodding, plugging, preoccupied, pressing, rapt, relentless, resolute, resounding, sedulous, single-minded, sleepless, slogging, stable, steadfast, steady, stubborn, taxing, teasing, tenacious, tireless, unabating, uncompromising, unconquerable, undaunted, undiscouraged, undrooping, unfailing, unfaltering, unflagging, unflinching, unintermitting, uninterrupted, unnodding, unrelaxing, unrelenting, unremitting, unsleeping, unswerving, untiring, unwavering, unwearied, unwearying, unwinking, unyielding, urgent, utterly attentive, weariless, wheedling