Why this word is great
GUILEFULNESS — [Noun] The quality of being guileful; cunning or deceit. From Middle English gilefulnesse, from guileful ("cunning, deceitful") + -ness ("state or quality"). Unlike "cunning" (which suggests a sharper, tactical cleverness) or "artlessness" (which implies an unguarded honesty), guilefulness is the velvet glove over the iron hand—deception polished to an art. It is the practiced smile of a diplomat who means the opposite of what he says, the flawless counterfeit bill passed unnoticed in a busy market, or the way a cat will purr and rub against your leg while calculating the distance to the unattended fish on the counter. A world without guilefulness would be either impossibly pure or unbearably dull.