To engage in outrageous flattery. The term comes from the fifteenth-century Blarney Castle, near Cork, Ireland, which has a triangular piece of engraved limestone embedded high on its wall. According to legend, anyone who could reach the stone and kiss it would be rewarded with acquiring the ability to cajole and flatter with great eloquence. To indulge tourists, the modern-day Irish have provided a substitute stone that is easier to reach and is, they claim, equally effective. The noun blarney has meant “inflated nonsense” since about 1800.