The Collaborative International Dictionary of English v.0.48:

Merry-go-round \Mer"ry-go`-round"\, n.
   Any revolving contrivance for affording amusement; esp., a
   group of seats in the shape of hobbyhorses or other fanciful
   animals, arranged in a circle on a platform that is rotated
   by a mechanical drive, often to the accompaniment of music;
   the seats often move up and down in synchrony with the
   rotation; -- called also carousel. It is employed primarily
   for the amusement of children, and is typically found at an
   amusement park.
   [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

carousel \carousel\ (k[a^]r`[-o]*s[e^]l"), n.
   1. a continuous belt oriented horizontally or
      near-horizontally around a central structure, driven in a
      circular motion by some mechanism, which carries luggage
      delivered from the luggage hold of an airplane to air
      travelers; -- used at airports.

   Syn: luggage carousel.
        [WordNet 1.5]

   2. same as merry-go-round.

   Syn: merry-go-round, roundabout, whirligig.
        [WordNet 1.5]

WordNet (r) 3.0 (2006):

carousel
    n 1: a conveyer belt that carries luggage to be claimed by air
         travelers [syn: carousel, carrousel, luggage
         carousel, luggage carrousel]
    2: a large, rotating machine with seats for children to ride or
       amusement [syn: carousel, carrousel, merry-go-round,
       roundabout, whirligig]