sty¹ / stī/ • n. a pigpen.• v. (sties, stied) [tr.] archaic keep (a pig) in a sty: the most beggarly place that ever pigs were stied in.sty² (also stye) • n. (pl. sties / stīz/ or styes) an inflamed swelling on the edge of an eyelid, caused by bacterial infection of the gland at the base of an eyelash.

sty1, stye inflamed swelling on the edge of an eyelid. XVII. Deduced from dial. styany (XV), prop. eye affected with a sty (apprehended as sty-on-eye), f. synon. styan (:- OE. stīġend, lit. ‘riser’, prp. used sb. of stīġan rise, ascend, climb) + EYE. OE. str. vb. stīġan corr. to OS., OHG. stīgan (Du. stijgen, G. steigen), ON. stíga, Goth. steigan :- Gmc. *stīʒan, f. *stī́ʒ- *staiʒ- :- IE. *steigh-, *stoigh-, stī́gh- advance, go, rise, repr. by Gr. steíkhein.

sty2 enclosed place for swine. XIII. repr. OE. *stī (as in stīfearh ‘sty-pig’), perh. identical with stiġ hall, corr. to ON. *stí (in svínstí swine-sty); :- Gmc. *stijam, of which a parallel formation *stijōn is repr. by MLG. stege, MDu. swijnstije, ON. stía pen, fold.