obstinate

persistent stubborn pertinacious adamant ardent grim bent on bullheaded certain chronic confirmed determined diehard dogged hard-hearted hard-nosed hardheaded headstrong immovable incalcitrant inflexible irrefragable insistent intractable intransigent intrepid inveterate mulish obdurate obstreperous peevish peremptory pigheaded recalcitrant refractory resolute resolved rigid self-willed stalwart staunch steadfast steady stubborn as a mule sullen tenacious terminal thran thwart tough truculent unbending uncompromising unyielding vehement wilful willful

compromising transigent flexible sycophantic yielding