die-hardism

noun as in grimness

noun as in implacability

noun as in implacableness

noun as in incompliance

noun as in incompliancy

noun as in inexorability

noun as in inexorableness

noun as in inflexibility

noun as in inflexibleness

noun as in intransigence

noun as in intransigency

noun as in obduracy

noun as in obdurateness

noun as in relentlessness

noun as in remorselessness

noun as in rigidity

noun as in rigidness