1. Not pleasant, not easy, or not likely to be wished for: Hank had the unenviable task of breaking the bad news about the accident to his friend's family.
2. Hard to deal with, especially causing pain or embarrassment: Wayne's brother had the unenviable challenge to significantly reduce his over-weight condition.
3. Not easy; requiring great physical or mental effort to accomplish or to comprehend and to endure: The university students in the computer class were given a difficult and an unenviable task to perform for the professor.
4. Etymology: envy comes from Old French envie "envy, jealousy, rivalry", from Latin invidia, "envy, jealousy", from invidus, "envious", from invidere, "envy"; earlier it meant "look at (with malice), cast an evil eye upon", from in- "on, upon" + videre, "to see".

Unenviable is a combination of un-, "not" + enviable, "a reference to a resentful or unhappy feeling of wanting somebody else's success, good fortune, qualities, or possessions".