The Collaborative International Dictionary of English v.0.48:

Oblate \Ob*late"\, a. [L. oblatus, used as p. p. of offerre to
   bring forward, offer, dedicate; ob (see Ob-) + latus borne,
   for tlatus. See Tolerate.]
   [1913 Webster]
   1. (Geom.) Flattened or depressed at the poles; as, the earth
      is an oblate spheroid.
      [1913 Webster]

   2. Offered up; devoted; consecrated; dedicated; -- used
      chiefly or only in the titles of Roman Catholic orders.
      See Oblate, n.
      [1913 Webster]

   Oblate ellipsoid or Oblate spheroid (Geom.), a solid
      generated by the revolution of an ellipse about its minor
      axis; an oblatum. Contrasted with prolate spheroid. See
      Ellipsoid of revolution, under Ellipsoid.
      [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Oblate \Ob*late"\, n. [From Oblate, a.] (R. C. Ch.)
      (a) One of an association of priests or religious women
          who have offered themselves to the service of the
          church. There are three such associations of priests,
          and one of women, called oblates.
      (b) One of the Oblati.
          [1913 Webster]

WordNet (r) 3.0 (2006):

oblate
    adj 1: having the equatorial diameter greater than the polar
           diameter; being flattened at the poles [syn: oblate,
           pumpkin-shaped] [ant: prolate, watermelon-shaped]
    n 1: a lay person dedicated to religious work or the religious
         life