adamant, assiduous, badgered, baited, balking, balky, bedeviled, beset, bigoted, bugged, bulldogged, bulletheaded, bullheaded, bullyragged, case-hardened, chivied, constant, continuing, deviled, diligent, dogmatic, enduring, faithful, fanatic, fretted, harassed, hardheaded, harried, haunted, headstrong, heckled, hectored, hounded, immutable, inalterable, indefatigable, indomitable, industrious, inexorable, insistent, intolerant, invincible, lasting, loyal, mulish, needled, never-tiring, nipped at, obdurate, obstinate, opinionated, overzealous, patient, patient as Job, permanent, persecuted, perseverant, persevering, persistent, persisting, pertinacious, pestered, picked on, pigheaded, plagued, plodding, plugging, preoccupied, ragged, rapt, relentless, resolute, restive, rigid, sedulous, self-willed, set, single-minded, sleepless, slogging, stable, steadfast, steady, stiff-necked, strong-willed, strongheaded, stubborn, sulky, sullen, teased, tenacious, tireless, tormented, unabating, unbending, unconquerable, uncooperative, undaunted, undiscouraged, undrooping, unfailing, unfaltering, unflagging, unflinching, unintermitting, uninterrupted, unnodding, unregenerate, unrelaxing, unrelenting, unremitting, unsleeping, unswerving, untiring, unwavering, unwearied, unwearying, unwinking, utterly attentive, vexed, weariless, willful, worried, worried sick, worried stiff