janus Meaning, Definition & Usage

  1. noun (Roman mythology) the Roman god of doorways and passages; is depicted with two faces on opposite sides of his head

WordNet

Ja"nus noun
Etymology
L. See January.
Definitions
  1. (Rom. Antiq.) A Latin deity represented with two faces looking in opposite directions. Numa is said to have dedicated to Janus the covered passage at Rome, near the Forum, which is usually called the Temple of Janus. This passage was open in war and closed in peace. Dr. W. Smith.

Webster 1913