[1] : The Collaborative International Dictionary of English v.0.48

couplet \coup"let\ -l?t, n. f. couplet, dim. of couple. see
   couple, n. 
   two taken together; a pair or couple; especially two lines of
   verse that rhyme with each other.
   1913 webster

         a sudden couplet rushes on your mind.    --crabbe.
   1913 webster
see also:
couple 

[2] : WordNet (r) 2.0

couplet
     n 1: two items of the same kind syn: couple, pair, twosome,
           twain, brace, span, yoke, distich, duo, duet,
           dyad, duad
     2: a stanza consisting of two successive lines of verse;
        usually rhymed
see also:
couple pair twosome twain brace span 
yoke distich duo duet dyad 
duad 

[3] : Moby Thesaurus II by Grady Ward, 1.0

56 moby thesaurus words for "couplet":
   spenserian stanza, antistrophe, book, both, brace, burden, canto,
   chorus, couple, distich, double harness, doublet, duad, duet, duo,
   dyad, envoi, epode, heptastich, hexastich, line, match, mates,
   measure, monostich, octastich, octave, octet, ottava rima, pair,
   pentastich, quatrain, refrain, rhyme royal, septet, sestet,
   set of two, sextet, span, stanza, stave, strain, strophe, syllable,
   team, tercet, terza rima, tetrastich, the two, triplet, tristich,
   twain, two, twosome, verse, yoke

Couplet >> C Words
Couplet, definition of term: Couplet
couplet_pag1.html

Heroic Couplet >> H Words
Heroic Couplet, definition of term: Heroic Couplet
heroic+couplet_pag1.html