Chro"mi*um (?), n. [NL., fr. Gr. &?; color.] (Chem.) A comparatively rare element occurring most abundantly in the mineral chromite. Atomic weight 52.5. Symbol Cr. When isolated it is a hard, brittle, grayish white metal, fusible with difficulty. Its chief commercial importance is for its compounds, as potassium chromate, lead chromate, etc., which are brilliantly colored and are used dyeing and calico printing. Called also chrome.

• a metallic chemical element (symbol Cr) with an atomic number of 24.