adj. 25B6; adjective
his inflexible attitude : STUBBORN, obstinate, obdurate, intractable, intransigent, unbending, immovable, unaccommodating; hidebound, single-minded, pig-headed, mulish, uncompromising, adamant, firm, resolute, diehard, dyed-in-the-wool; formal refractory.
inflexible rules : UNALTERABLE, unchangeable, immutable, unvarying; firm, fixed, set, established, entrenched, hard and fast; stringent, strict.
an inflexible structure : RIGID, stiff, unyielding, unbending, unbendable; hard, firm, inelastic.
accommodating, pliable.