Synonyms and related words :
adamant, adamantine, bullheaded, closed to, headstrong, immovable, immutable, impersuadable, impersuasible, impervious, inductile, inelastic, inextensible, inextensile, inextensional, inflexible, intractable, intractile, irresilient, mulish, nonelastic, nonstretchable, obstinate, perverse, pigheaded, self-willed, stubborn, unalterable, unamenable, unbending, unextendible, unextensible, unflexible, ungiving, unimpressionable, uninfluenceable, unlimber, unmalleable, unmovable, unpersuadable, unpliant, unreceptive, unresponsive, unsuggestible, unsusceptible, unswayable, untractable, unyielding