Synonyms for inflexible

adamant, demanding, exacting, fixed, hard-line, headstrong, immovable, immutable, industrious, intransigent, invariable, obstinate, over-exacting, overstrict, resolute, rigid, rigorous, staunch, stern, stiff, strict, stringent, strong-minded, stubborn, unaccommodating, unadaptable, unalterable, unbendable, unbending, uncompromising, undeviating, unfluctuating, unshakeable, unwavering, unyielding, willful