Hem"or*rhoids (?), n. pl. [L. haemorrhoidae, pl., Gr. &?;, sing., &?; (sc. &?;), pl., veins liable to discharge blood, hemorrhoids, fr. &?; flowing with blood; a"i^ma blood + &?; to flow: cf. F. hémorroïdes, hémorrhoïdes. See Rheum.] (Med.) Livid and painful swellings formed by the dilation of the blood vessels around the margin of, or within, the anus, from which blood or mucus is occasionally discharged; piles; emerods. [The sing. hemorrhoid is rarely used.]