The Collaborative International Dictionary of English v.0.48:

Combine \Com*bine"\ (k[o^]m*b[imac]n"), v. t. [imp. & p. p.
   Combined (k[o^]m*b[imac]nd"); p. pr. & vb. n. Combining.]
   [LL. combinare, combinatum; L. com- + binus, pl. bini, two
   and two, double: cf. F. combiner. See Binary.]
   1. To unite or join; to link closely together; to bring into
      harmonious union; to cause or unite so as to form a
      homogeneous substance, as by chemical union.
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            So fitly them in pairs thou hast combined. --Milton.
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            Friendship is the cement which really combines
            mankind.                              --Dr. H. More.
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            And all combined, save what thou must combine
            By holy marriage.                     --Shak.
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            Earthly sounds, though sweet and well combined.
                                                  --Cowper.
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   2. To bind; to hold by a moral tie. [Obs.]
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            I am combined by a sacred vow.        --Shak.
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WordNet (r) 3.0 (2006):

combining
    n 1: an occurrence that results in things being united [syn:
         combining, combine]
    2: the act of combining things to form a new whole [syn:
       combination, combining, compounding]

Moby Thesaurus II by Grady Ward, 1.0:

58 Moby Thesaurus words for "combining":
   accompanying, accordant, agreeing, associate, associated,
   associative, at one with, blending, coacting, coactive, coadunate,
   coalescent, coalescing, coincident, collaborative, collective,
   collusive, combinative, combinatory, combined, concerted,
   concomitant, concordant, concurrent, concurring, conjoint,
   conjunctival, conjunctive, connecting, connectional, connective,
   consilient, conspiratorial, cooperant, cooperative, coordinate,
   corporational, coworking, federal, federative, fusing, harmonious,
   incorporating, incorporative, joint, meeting, merging, parasitic,
   saprophytic, symbiotic, synchronous, synergetic, synergic,
   synergistic, unific, unifying, united, uniting