Unbending

strict firm hard stiff inflexible tough stubborn severe unyielding uncompromising relentless obstinate inexorable resolute uptight aloof formal distant reserved crisp unrelenting incompliant intractable inelastic unswayable hard-line unflexible single-minded standing pat dug in standing one’s ground holding one’s ground sticking to one’s guns hold the line hold the fort set in stone locked in hard as nails do or die