Ha"loid (hā"loid or hăl"oid), a. [Gr. "a`ls, "alo`s salt + -oid: cf. F. haloïde.] (Chem.) Resembling salt; -- said of certain binary compounds consisting of a metal united to a negative element or radical, and now chiefly applied to the chlorides, bromides, iodides, and sometimes also to the fluorides and cyanides. -- n. A haloid substance.