54 synonyms for persistent such as continual, assiduous, chronic, and constant. Persistent is an adjective, and its antonyms are intermittent, occasional, and irresolute.
Assiduous, determined, diligent, dogged, importunate, indefatigable, insistent, intransigent, obdurate, obstinate, patient, persevering, pertinacious, purposeful, relentless, resolute, sedulous, single-minded, stubborn, tenacious, tireless, unflagging, unrelenting, untiring, and unwavering.
Chronic, constant, continual, continuing, continuous, endless, frequent, habitual, incessant, interminable, lasting, lingering, nagging, never-ending, non-stop, permanent, perpetual, relentless, repeated, steady, sustained, unbroken, unceasing, unending, uninterrupted, unrelenting, unrelieved, and unremitting.