Definition of Janus in US English:


proper noun

  • 1Roman Mythology
    An ancient Italian deity, guardian of doorways and gates and protector of the state in time of war. He is usually represented with two faces, so that he looks both forward and backward.

    equivocator, trimmer, vicar of bray
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  • 2Astronomy
    A moon of Saturn, sixth closest to the planet, discovered in 1966, and having a diameter of 118 miles (190 km).