Unbending

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