The Collaborative International Dictionary of English v.0.48:

Conjoint \Con*joint"\, a. [F. conjoint, p. p. of conjoindre. See
   Conjoin, and cf. Conjunct.]
   United; connected; associated. "Influence conjoint."
   --Glover.
   [1913 Webster]

   Conjoint degrees (Mus.), two notes which follow each other
      immediately in the order of the scale, as ut and re.
      --Johnson.

   Conjoint tetrachords (Mus.), two tetrachords or fourths,
      where the same note is the highest of one and the lowest
      of the other; -- also written conjunct.
      [1913 Webster]

WordNet (r) 3.0 (2006):

conjoint
    adj 1: consisting of two or more associated entities; "the
           interplay of these conjoined yet opposed factors";
           "social order and prosperity, the conjoint aims of
           government"- J.K.Fairbank [syn: conjoined, conjoint]

Moby Thesaurus II by Grady Ward, 1.0:

92 Moby Thesaurus words for "conjoint":
   accessory, accompanying, accordant, agreeing, amalgamated,
   assimilated, associate, associated, at one with, attendant,
   attending, blended, coacting, coactive, coadunate, coefficient,
   coincident, collaborative, collateral, collective, collectivistic,
   collusive, combinative, combinatory, combined, combining, common,
   communal, communistic, commutual, compact, comprehensive,
   concerted, concomitant, concordant, concurrent, concurring,
   conjugate, conjunct, conjunctive, connective, consilient,
   consolidated, conspiratorial, cooperant, cooperative, coordinate,
   corporate, correlative, coupled, coworking, eclectic, fellow,
   fused, general, harmonious, in common, inclusive, incorporated,
   integrated, joined, joint, meeting, merged, mixed, mutual, one,
   paired, parallel, parasitic, popular, public, reciprocal,
   respective, saprophytic, shared, simultaneous, social, socialistic,
   societal, symbiotic, synchronous, syncretistic, syncretized,
   synergetic, synergic, synergistic, synthesized, twin, two-way,
   united, uniting