The Collaborative International Dictionary of English v.0.48:

Explicit \Ex"pli*cit\ [LL., an abbreviation of explicitus (est
   liber) the book (which anciently was a roll of parchment) is
   unfolded (and, of course, "finished"). See Explicit, a.]
   A word formerly used (as finis is now) at the conclusion of a
   book to indicate the end.
   [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Explicit \Ex*plic"it\, a. [L. explicitus; p. p. of explicare to
   unfold: cf. F. explicite. See Explicate, Exploit.]
   1. Not implied merely, or conveyed by implication; distinctly
      stated; plain in language; open to the understanding;
      clear; not obscure or ambiguous; express; unequivocal; as,
      an explicit declaration. Opposite of implicit.
      [1913 Webster]

            The language of the charter was too explicit to
            admit of a doubt.                     --Bancroft.
      [1913 Webster]

   2. Having no disguised meaning or reservation; unreserved;
      outspoken; -- applied to persons; as, he was earnest and
      explicit in his statement.
      [1913 Webster]

   Explicit function. (Math.) See under Function.

   Syn: Express; clear; plain; open; unreserved; unambiguous.

   Usage: Explicit, Express. Explicit denotes a setting
          forth in the plainest language, so that the meaning
          can not be misunderstood; as, an explicit promise.
          Express is stronger than explicit: it adds force to
          clearness. An express promise or engagement is not
          only unambiguous, but stands out in bold relief, with
          the most binding hold on the conscience. An explicit
          statement; a clear and explicit notion; explicit
          direction; no words can be more explicit. An explicit
          command; an express prohibition. "An express
          declaration goes forcibly and directly to the point.
          An explicit declaration leaves nothing ambiguous."
          --C. J. Smith.
          [1913 Webster]

WordNet (r) 3.0 (2006):

explicit
    adj 1: precisely and clearly expressed or readily observable;
           leaving nothing to implication; "explicit instructions";
           "she made her wishes explicit"; "explicit sexual scenes"
           [syn: explicit, expressed] [ant: implicit,
           inexplicit]
    2: in accordance with fact or the primary meaning of a term
       [syn: denotative, explicit]