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"
a noticeable deterioration in performance or quality; "the team went into a slump"; "a gradual slack in output"; "a drop-off in attendance"; "a falloff in quality"
fall heavily or suddenly; decline markedly; "The real estate market fell off"
fall or sink heavily; "He slumped onto the couch"; "My spirits sank"
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"
(physiology) metabolic equilibrium actively maintained by several complex biological mechanisms that operate via the autonomic nervous system to offset disrupting changes