Synonyms to hard-line

inflexible, adamant, adamantine, at a standstill, cast-iron, certain, changeless, closed to, constant, determinate, determined, dogged, dour, dyed, established, fated, fateful, firm, fixed, flinty, frozen, fundamentalist, grim, hard, hard and fast, hard-core, headstrong, hidebound, immobile, immotile, immotive, immovable, immutable, impersuadable, impersuasible, impervious, implacable, impliable, inalterable, indefeasible, indomitable, inductile, inelastic, ineluctable, inescapable, inevasible, inevitable, inexorable, inextensible, inextensile, inextensional, intractable, intractile, intransigent, invariable, invincible, iron, ironbound, ironclad, ironhanded, irreconcilable, irremovable, irresilient, irresistible, irrevocable, loyal, mulish, muscle-bound, necessary, nonelastic, nonstretchable, obdurate, obstinate, orthodox, pat, pigheaded, procrustean, purist, puristic, puritan, puritanic, refractory, relentless, resistless, resolute, resolved, rigid, rigorist, rigoristic, rigorous, rock-ribbed, rockbound, set, settled, severe, single-minded, sot, standpat, stationary, staunch, steadfast, steady, st