BOSS. (1) (From the O. Eng. boce, a swelling, cf. Ital. bozza, and Fr. bosse, possibly connected with the O. Ger. bōzan, to beat), a round protuberance; the projecting centre or "umbo" of a buckler; in geology a projection of rock through strata of another species; in architecture, the projecting keystone of the ribs of a vault which masks their junction; the term is also applied to similar projecting blocks at every intersection. The boss was often richly carved, generally with conventional foliage but sometimes with angels, animals or grotesque figures. The boss was also employed in the flat timber ceilings of the 15th century, where it formed the junction of cross-ribs. (2) (From the Dutch baas, a word used by the Dutch settlers in New York for "master," and so generally used by the Kaffirs in South Africa; connected with the Ger. Base, cousin, meaning a "chief kinsman," the head of a household or family), a colloquial term, first used in America, for an employer, a foreman, and generally any one who gives orders, especially in American political slang for the manager of a party organization.
Note - this article incorporates content from Encyclopaedia Britannica, Eleventh Edition, (1910-1911)