Diminutive of Elizabeth, from Hebrew Elisheva meaning 'God is my oath.'
Bessy is one of the oldest pet-forms of Elizabeth, itself derived from the Hebrew Elisheba, meaning "my God is an oath" or, in some interpretations, "my God is abundance." The transformation from Elizabeth to Bessy followed medieval English naming conventions where the initial syllable was dropped and a familiar suffix added, producing a whole family of nicknames — Bess, Bessie, Betsy, Betty — each with its own distinct social register. Bessy with a "y" carries a slightly more rustic, unhurried quality than its sister spelling Bessie.
In the Elizabethan era, "Good Queen Bess" was the affectionate popular name for Elizabeth I, and variations like Bessy circulated freely among common people who would never have dared address royalty so familiarly in person. Through the seventeenth and eighteenth centuries, Bessy was standard countryside English — it appears in Burns's poetry, in Scottish folk ballads, and in the pastoral literature that romanticized rural life. The name also became attached to dairy cattle, a familiarity that eventually nudged it downward in social estimation as the nineteenth century valorized more formal names.
Bessy reached peak use in the Victorian era before retreating through the twentieth century as Elizabeth's longer forms regained favor. Today it carries the warm, well-worn quality of a name found in a great-grandmother's Bible — unpretentious, affectionate, and ready for the same revival that has already brought Bessie back to popularity. It belongs to a lineage of queens and farmers alike, which is perhaps its greatest charm.