Word Origin & History
O.E. borian "to bore through, perforate," from bor "auger," from P.Gmc. *buron (cf. O.N. bora, Swed. borra, O.H.G. boron, M.Du. boren, Ger. bohren), from PIE base *bher- (2) "to cut with a sharp point" (cf. Gk. pharao "I plow," L. forare "to bore, pierce," O.C.S. barjo "to strike, fight," Albanian brime
"hole"). The meaning "diameter of a tube" is first recorded 1570s; hence figurative slang full bore (1936) "at maximum speed," from notion of unchoked carburetor on an engine. Sense of "be tiresome or dull" first attested 1768, a vogue word c.1780-81 according to Grose; possibly a figurative extension of "to move forward slowly and persistently," as a boring tool does.
"The secret of being a bore is to tell everything." [Voltaire, "Sept Discours en Vers sur l'Homme," 1738]