The Collaborative International Dictionary of English v.0.48:

Disjunct \Dis*junct"\ (d[i^]s*j[u^][ng]kt"), a. [L. disjunctus,
   p. p. of disjungere to disjoin. See Disjoin, and cf.
   Disjoint.]
   1. Disjoined; separated. [R.]
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   2. (Zool.) Having the head, thorax, and abdomen separated by
      a deep constriction.
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   Disjunct tetrachords (Mus.), tetrachords so disposed to
      each other that the gravest note of the upper is one note
      higher than the acutest note of the other.
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