unexpected -
not expected or anticipated; "unexpected guests"; "unexpected news"
expected considered likely or probable to happen or arrive; "prepared for the expected attack"
surprising causing surprise or wonder or amazement; "the report shows a surprising lack of hard factual data"; "leaped up with surprising agility"; "she earned a surprising amount of money"
unannounced,
unheralded,
unpredicted without warning or announcement; "they arrived unannounced"; "a totally unheralded telegram that his daughter...died last night"- M.A.D.Howe
out of the blue,
unanticipated,
unforeseen,
unlooked-for 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"
unhoped,
unhoped-for,
unthought,
unthought-of 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"
