The Collaborative International Dictionary of English v.0.48:

Adnate \Ad"nate\, a. [L. adnatus, p. p. of adnasci. See
   Adnascent, and cf. Agnate.]
   1. (Physiol.) Grown to congenitally.
      [1913 Webster]

   2. (Bot.) Growing together; -- said only of organic cohesion
      of unlike parts.
      [1913 Webster]

            An anther is adnate when fixed by its whole length
            to the filament.                      --Gray.
      [1913 Webster]

   3. (Zool.) Growing with one side adherent to a stem; -- a
      term applied to the lateral zooids of corals and other
      compound animals.
      [1913 Webster]

WordNet (r) 3.0 (2006):

adnate
    adj 1: of unlike parts or organs; growing closely attached; "a
           calyx adnate to the ovary" [ant: connate]