The Collaborative International Dictionary of English v.0.48:

Elater \E*lat"er\, n.
   One who, or that which, elates.
   [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Elater \El"a*ter\, n. [NL., fr. Gr. ? driver, fr. ? to drive.]
   1. (Bot.) An elastic spiral filament for dispersing the
      spores, as in some liverworts.
      [1913 Webster]

   2. (Zo["o]l.) Any beetle of the family Elaterid[ae], having
      the habit, when laid on the back, of giving a sudden
      upward spring, by a quick movement of the articulation
      between the abdomen and thorax; -- called also click
      beetle, spring beetle, and snapping beetle.
      [1913 Webster]

   3. (Zo["o]l.) The caudal spring used by Podura and related
      insects for leaping. See Collembola.
      [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Elater \El"a*ter\, n. (Chem.)
   The active principle of elaterium, being found in the juice
   of the wild or squirting cucumber (Ecballium agreste,
   formerly Motordica Elaterium) and other related species. It
   is extracted as a bitter, white, crystalline substance, which
   is a violent purgative.
   [1913 Webster]

WordNet (r) 3.0 (2006):

elater
    n 1: any of various widely distributed beetles [syn: elaterid
         beetle, elater, elaterid]