steadfastness

Firmess is likely misspelled.

Firmess has no English definition.

As a noun steadfastness is

loyalty in the face of trouble and difficulty.

As nouns the difference between taxonomy and steadfastness

is that taxonomy is the science or the technique used to make a classification while steadfastness is loyalty in the face of trouble and difficulty.

As nouns the difference between steadfastness and unflinchingness

is that steadfastness is loyalty in the face of trouble and difficulty while unflinchingness is the state or condition of being unflinching; steadfastness, resoluteness.