The Collaborative International Dictionary of English v.0.48:

Splice \Splice\ (spl[imac]s), v. t. [imp. & p. p. Spliced
   (spl[imac]st); p. pr. & vb. n. Splicing.] [D. splitsen,
   splitten; akin to G. splissen, Sw. splissa, Dan. splisse, and
   E. split; -- from the dividing or splitting the ends into
   separate strands. See Split, v. t.]
   1. To unite, as two ropes, or parts of a rope, by a
      particular manner of interweaving the strands, -- the
      union being between two ends, or between an end and the
      body of a rope.
      [1913 Webster]

   2. To unite, as spars, timbers, rails, etc., by lapping the
      two ends together, or by applying a piece which laps upon
      the two ends, and then binding, or in any way making fast.
      [1913 Webster]

   3. To unite in marriage. [Slang]
      [1913 Webster]

   Splice grafting.ee under Grafting.

   To splice the main brace (Naut.), to give out, or drink, an
      extra allowance of spirits on occasion of special exposure
      to wet or cold, or to severe fatigue; hence, to take a
      dram.
      [1913 Webster]

Moby Thesaurus II by Grady Ward, 1.0:

48 Moby Thesaurus words for "spliced":
   affiliate, affiliated, allied, assembled, associate, associated,
   banded together, bound, bracketed, collateral, collected,
   conjoined, conjugate, connected, copulate, correlated, coupled,
   gathered, hand-in-glove, hand-in-hand, implicated, incorporated,
   integrated, interlinked, interlocked, interrelated, intimate,
   involved, joined, knotted, leagued, linked, matched, mated, merged,
   of that ilk, of that kind, paired, parallel, related, tied,
   twinned, undivided, united, unseparated, wed, wedded, yoked