adj. so unexpected as to have not been imagined; "an unhoped-for piece of luck"; "an unthought advantage"; "an unthought-of place to find the key"

adj. made necessary by an unexpected situation or emergency; "a forced landing"

adj. characterized by often poignant difference or incongruity between what is expected and what actually is; "madness, an ironic fate for such a clear thinker"; "it was ironical that the well-planned scheme failed so completely"

adj. without warning or announcement; "they arrived unannounced"; "a totally unheralded telegram that his daughter...died last night"- M.A.D.Howe

adj. not anticipated; "unanticipated and disconcerting lines of development"- H.W.Glidden; "unforeseen circumstances"; "a virtue unlooked-for in people so full of energy"; "like a bolt out of the blue"

adj. used of an unexpected defeat of a team favored to win; "the Bills' upset victory over the Houston Oilers"

adj. not prepared or ready for