"peripatetic quack; one who sells nostrums at fairs, etc.," in Johnson's words, "a doctor that mounts a bench in the market, and boasts his infallible remedies and cures;" 1570s, from Italian montambanco, contraction of monta in banco "quack, juggler," literally "mount on bench" (to be seen by crowd), from monta, imperative of montare "to mount" (see mount (v.)) + banco, variant of banca "bench," from a Germanic source (see bench (n.)). Figurative and extended senses, in reference to any impudent pretender or charlatan, are from 1580s. Related: Mountebankery.
also Sanscrit, ancient sacred language of India, 1610s, from Sanskrit samskrtam "put together, well-formed, perfected," neuter of samskrta, from sam "together" (from PIE root *sem- (1) "one; as one, together with") + krta- "to make, do, perform" (from PIE *kwer- "to make, form;" see terato-). "[S]o called as being the cultivated or literary language, distinguished from the vulgar dialects, or, some say, because regarded as a perfect language, the speech of the gods, formed by infallible rules" [Century Dictionary]. It continued as a learned tongue long after it ceased to exist as a vernacular.
1879 as colloquial shortening of Metropolitan (n.) "member of the New York Metropolitan Base-Ball Club."
THE baseball season has opened, and along with the twittering of the birds, the budding of the trees, and the clattering of the truck, comes the news that the "Mets were beaten yesterday 17 to 5." It is an infallible sign of spring when the Mets are beaten 17 to 5, and we invariably put on our thinner clothing when we read that refreshing, though perennial news in the papers. [Life magazine, May 12, 1887]
Used variously to abbreviate other proper names beginning with Metropolitan, such as "Metropolitan Museum of Art" (N.Y.), by 1919; "Metropolitan Railway" (stock), by 1890; "Metropolitan Opera Company (N.Y.), by 1922. Related: Mets.