dysprosium (n.)

element, obtained 1906 from an earth discovered in 1886, the last to be extracted from the complex earth called yttria, and named dysprosia in reference to the difficulty of obtaining it, from Greek dysprositos "hard to get at, difficult of access," from dys- "bad, difficult" (see dys-) + prositos "approachable." With metallic element suffix -ium.