blarney (n.)

"exceedingly complimentary language," 1796, from the Blarney Stone (which is said to make a persuasive flatterer of any who kiss it), built high into a battlement of a medieval castle of that name near Cork, Ireland. Bartlett connects the meaning of the word to the difficulty of the attempt to get close enough to the stone to kiss it: "to have ascended it, was proof of perseverance, courage, and agility, whereof many are supposed to claim the honor who never achieved the adventure." Thus to have kissed the Blarney Stone came to mean "to tell wonderful tales" ["Dictionary of Americanisms," 1848]. The word reached wide currency through Lady Blarney, the smooth-talking flatterer in Goldsmith's "Vicar of Wakefield" (1766). As a verb from 1803.