SEM'I-METAL, noun [semi and metal.] An imperfect metal, or rather a metal that is not malleable, as bismuth, arsenic, nickel, cobalt, zinc, antimony, maganese, tungsten, molybden, and uranite. The name however is usually given to the regulus of these substances.
Source: Webster's 1828 American Dictionary ↗ · public-domain · returned verbatim, no AI