1650s, from heir + -ess. A female heir, but especially a woman who has inherited, or stands to inherit, considerable wealth.
Entries linking to heiress
heir n.
"one who inherits, or has right of inheritance in, the property of another," c. 1300, from Anglo-French heir, Old French oir "heir, successor; heritage, inheritance," from Latin heredem (nominative heres) "heir, heiress" (see heredity). Heir apparent (late 14c.) has the French order of noun-adjective, though it was not originally so written in English. It is the heir of one still alive whose right is clear. After death the heir apparent becomes the heir-at-law. Related: Heir-apparency.
-ess
fem. suffix, from French -esse, from Late Latin -issa, from Greek -issa (cognate with Old English fem. agent suffix -icge); rare in classical Greek but more common later, in diakonissa "deaconess" and other Church terms picked up by Latin.