heiress

As a noun heiress

is a woman who stands to inherit.

As an adjective heirless is

without an heir.

As nouns the difference between taxonomy and heiress

is that taxonomy is the science or the technique used to make a classification while heiress is a woman who stands to inherit.

As nouns the difference between mistress and heiress

is that mistress is (archaic) used as the title of a married woman before her name now used only in the abbreviated form mrs while heiress is a woman who stands to inherit.

As nouns the difference between headmistress and heiress

is that headmistress is a female school principal while heiress is a woman who stands to inherit.

Heirer is likely misspelled.

Heirer has no English definition.

As a noun heiress is

a woman who stands to inherit.

As nouns the difference between heiress and coheiress

is that heiress is a woman who stands to inherit while coheiress is one of several who are heiresses to an estate.

As nouns the difference between heiress and inheritrix

is that heiress is a woman who stands to inherit while inheritrix is female inheritor; heiress.