The Collaborative International Dictionary of English v.0.48:

Disjunctive \Dis*junc"tive\, a. [L. disjunctivus: cf. F.
   disjonctif.]
   1. Tending to disjoin; separating; disjoining.
      [1913 Webster]

   2. (Mus.) Pertaining to disjunct tetrachords. "Disjunctive
      notes." --Moore (Encyc. of Music).
      [1913 Webster]

   Disjunctive conjunction (Gram.), one connecting
      grammatically two words or clauses, expressing at the same
      time an opposition or separation inherent in the notions
      or thoughts; as, either, or, neither, nor, but, although,
      except, lest, etc.

   Disjunctive proposition, a proposition in which the parts
      are connected by disjunctive conjunctions, specifying that
      one of two or more propositions may hold, but that no two
      propositions may hold at the same time; as it is either
      day or night.

   Disjunctive syllogism (Logic), one in which the major
      proposition is disjunctive; as, the earth moves in a
      circle or an ellipse; but in does not move in a circle,
      therefore it moves in an ellipse.
      [1913 Webster]

WordNet (r) 3.0 (2006):

disjunctive conjunction
    n 1: the conjunctive relation of units that expresses the
         disjunction of their meanings