T'ARNISH, verb transitive 1. To sully; to soil by an alteration induced by the air, or by dust and the like; to diminish or destroy luster; as, to tarnish a metal; to tarnish gilding; to tarnish the brightness or beauty of color. 2. To diminish or destroy the purity of; as to tarnish reputation or honor. T'ARNISH, verb intransitive To lose luster; to become dull; as, polished substances of gilding will tarnish in the course of time. Metals tarnish by oxydation.
Source: Webster's 1828 American Dictionary ↗ · public-domain · returned verbatim, no AI