(skuhl-DUHG-uh-ree): n from Scottish sculduddery: underhand dealing; trickery
Imagine the look on your sister's face when you find your sweater in her closet and shout "Skulduggery!" She probably wouldn't know exactly what face to make. Skulduggery is an obscure word, but for no real reason. It sounds so much more indignant than "trickery"— which sounds like a word Dora the Explorer would say. Skulduggery really packs a punch and gets the point across.