"the female person referred to," third person nominative fem. pronoun, used as a substitute for the name of a female or anything regarded as female, mid-12c., probably evolving from Old English seo, sio (accusative sie), fem. of the demonstrative pronoun (masc. se) "the," from PIE root *so- "this, that" (see the).
The Old English word for "she" was heo, hio, however by 13c. the pronunciation of this had converged by phonetic evolution with he "he," which apparently led to the fem. demonstrative pronoun being used in place of the pronoun (compare similar development in Dutch zij, German sie, Greek he, etc.).
The original h- survives in her. A relic of the Old English pronoun is in Manchester-area dialectal oo "she." As a noun meaning "a female human being, a woman," she is attested from early 14c. Also used to signify "female" with the names of other creatures (late 14c.; she-wolf, etc.). The attempted gender-neutral pronoun form s/he is attested by 1977.
updated on August 13, 2022