The first month of the Gregorian calendar, following the December of the previous year and preceding February. Abbreviation: Jan or Jan. / (rare) A female given name from English.

In January.

plural of January

plural of January

Any time in the middle of January.

Happening in the middle of January.

In the middle of January.

December 31

(finance) A hypothetical seasonal anomaly in the financial market where securities' prices increase in the month of January more than in any other month.

plural of January effect