expectation

Etymology

From Middle French expectation, from Latin exspectātiō, from exspectō (“expect”); synchronically analyzable as expect + -ation. Displaced native Old English wēn.

noun

1. The act or state of expecting or looking forward to an event as about to happen.
2. That which is expected or looked for.
   And so it had always pleased M. Stutz to expect great things from the dark young man whom he had first seen in his early twenties ; and his expectations had waxed rather than waned on hearing the faint bruit of the love of Ivor and Virginia—for Virginia, M. Stutz thought, would bring fineness to a point in a man like Ivor Marlay,[…]. 1922, Michael Arlen, “Ep./1/1”, in “Piracy”: A Romantic Chronicle of These Days
   Thus the B.R. diesel fleet today is composed of a rather assorted collection of designs. Some have proved to be remarkably satisfactory in service; others have so far not come up to expectations and I suppose it is doubtful whether any more orders for some types will be forthcoming. 1961 March, B.A. Haresnape, “Design on the railway”, in Trains Illustrated, page 145
3. The prospect of the future; grounds upon which something excellent is expected to occur; prospect of anything good to come, especially of property or rank.
4. The value of any chance (as the prospect of prize or property) which depends upon some contingent event.
5. (statistics) The first moment; the long-run average value of a variable over many independent repetitions of an experiment.
6. (statistics, colloquial) The arithmetic mean.
7. (medicine, rare) The leaving of a disease principally to the efforts of nature to effect a cure.