The Collaborative International Dictionary of English v.0.48:

Circumstantial \Cir`cum*stan"tial\, n.
   Something incidental to the main subject, but of less
   importance; opposed to an essential; -- generally in the
   plural; as, the circumstantials of religion. --Addison.
   [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

circumstantial \cir`cum*stan"tial\ (s[~e]r`k[u^]m*st[a^]n"shal),
   a. [Cf. F. circonstanciel.]
   [1913 Webster]
   1. Consisting in, or pertaining to, circumstances or
      particular incidents.
      [1913 Webster]

            The usual character of human testimony is
            substantial truth under circumstantial variety.
                                                  --Paley.
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   2. Incidental; relating to, but not essential.
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            We must therefore distinguish between the essentials
            in religious worship . . . and what is merely
            circumstantial.                       --Sharp.
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   3. Abounding with circumstances; detailing or exhibiting all
      the circumstances; minute; particular.
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            Tedious and circumstantial recitals.  --Prior.
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   Circumstantial evidence (Law), evidence obtained from
      circumstances, which necessarily or usually attend facts
      of a particular nature, from which arises presumption.
      According to some authorities circumstantial is
      distinguished from positive evidence in that the latter is
      the testimony of eyewitnesses to a fact or the admission
      of a party; but the prevalent opinion now is that all such
      testimony is dependent on circumstances for its support.
      All testimony is more or less circumstantial. --Wharton.

   Syn: See Minute.
        [1913 Webster]

WordNet (r) 3.0 (2006):

circumstantial
    adj 1: fully detailed and specific about particulars; "a
           circumstantial report about the debate"