D defs.my
Entry 1 sense Webster, 1913

Cometarium

· Com·e·ta·ri·um · IPA /ˌkɑməˈtɛɹi.əm/
01 n. An instrument, intended to represent the revolution of a comet round the sun.
  1. 1.
    An instrument, intended to represent the revolution of a comet round the sun.(Astron.)