Meaning

noun an infection of the sebaceous gland of the eyelid

originFirst recorded in the 17th century; probably a back-formation from Middle English styanye (first recorded in the 15th century), which in turn comes from Old English stīgend (“a small tumour on the edge of the eyelid, stye”), from the verb stīgan (“to climb, ascend, rise”) + Middle English eie (“eye”). Equivalent to sty + eye.

Etymology from Wiktionary, CC BY-SA 3.0