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Janus

American  
[jey-nuhs] / ˈdʒeɪ nəs /

noun

  1. an ancient Roman god of doorways, of beginnings, and of the rising and setting of the sun, usually represented as having one head with two bearded faces back to back, looking in opposite directions.

  2. Astronomy. a moon of the planet Saturn, located just outside the rings.


Janus 1 British  
/ ˈdʒeɪnəs /

noun

  1. a small inner satellite of Saturn

"Collins English Dictionary — Complete & Unabridged" 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Janus 2 British  
/ ˈdʒeɪnəs /

noun

  1. the Roman god of doorways, passages, and bridges. In art he is depicted with two heads facing opposite ways

"Collins English Dictionary — Complete & Unabridged" 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Janus Cultural  
  1. The Roman god of doors and gateways and hence of beginnings.


Discover More

The month of January is named after Janus.

Janus was pictured with two faces looking in opposite directions, one young and one old. Consequently, a hypocritical person is often called “Janus-faced.”

Etymology

Origin of Janus

< Latin, special use of jānus doorway, archway, arcade

Example Sentences

Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.

Before those pricings, there had only been five IPO pricings in the past month, according to Renaissance Capital data, with the largest IPO being $840 million on March 19 from Janus Living.

From MarketWatch • Apr. 16, 2026

This triggers a structural imbalance called a Janus reaction, which creates internal strain within the layers.

From Science Daily • Mar. 31, 2026

Banks face increased default risk and higher pay demands, potentially impacting earnings, according to Janus Henderson Investors.

From The Wall Street Journal • Mar. 31, 2026

Senior housing real estate firm Janus Living also went public in March, and shares are up almost 20% from their IPO price.

From Barron's • Mar. 25, 2026

Maybe it was a dream within my dream, but suddenly I imagined the two-headed god Janus shimmering in the air next to Daedalus, smiling as he tossed a silver key from hand to hand.

From "The Battle of the Labyrinth" by Rick Riordan