Synonyms:
- assiduous,
- balking,
- balky,
- bigoted,
- bulldogged,
- bulldoggish,
- bulletheaded,
- bullheaded,
- case-hardened,
- clamant,
- clamorous,
- constant,
- continuing,
- crying,
- demanding,
- diligent,
- dogged,
- dogmatic,
- draining,
- enduring,
- exacting,
- exigent,
- exorbitant,
- extortionate,
- faithful,
- fanatic,
- fixed,
- game,
- gamy,
- grasping,
- gritty,
- gutsy,
- gutty,
- hardheaded,
- headstrong,
- immutable,
- importunate,
- inalterable,
- indefatigable,
- indomitable,
- industrious,
- insistent,
- instant,
- intolerant,
- invincible,
- lasting,
- loud,
- loyal,
- mettlesome,
- mulish,
- nervy,
- never-tiring,
- obstinate,
- opinionated,
- overzealous,
- patient,
- patient as Job,
- permanent,
- perseverant,
- persevering,
- persistent,
- persisting,
- perverse,
- pigheaded,
- plodding,
- plucky,
- plugging,
- preoccupied,
- pressing,
- rapt,
- red-blooded,
- refractory,
- relentless,
- resolute,
- restive,
- sedulous,
- self-willed,
- set,
- single-minded,
- sleepless,
- slogging,
- spirited,
- spiritful,
- spunky,
- stable,
- steadfast,
- steady,
- stiff-necked,
- strong-willed,
- strongheaded,
- stubborn,
- sulky,
- sullen,
- taxing,
- tenacious,
- tireless,
- tough,
- unabating,
- unconquerable,
- uncooperative,
- undaunted,
- undiscouraged,
- undrooping,
- unfailing,
- unfaltering,
- unflagging,
- unflinching,
- unintermitting,
- uninterrupted,
- unnodding,
- unregenerate,
- unrelaxing,
- unrelenting,
- unremitting,
- unshakable,
- unsleeping,
- unswerving,
- untiring,
- unwavering,
- unwearied,
- unwearying,
- unwinking,
- unyielding,
- urgent,
- utterly attentive,
- weariless,
- willful