The Collaborative International Dictionary of English v.0.48:

Expectant \Ex*pect"ant\, a. [L.expectans, exspectans, p. pr. of
   expectare, exspectare: cf. F. expectant.]
   Waiting in expectation; looking for; (Med.) waiting for the
   efforts of nature, with little active treatment.
   [1913 Webster]

   Expectant estate (Law), an estate in expectancy. See under
      Expectancy.
      [1913 Webster]