jan
n. uncountablen. the short way to write January, which is the first month of the year. You often see this on calendars or in dates.
n. the standard abbreviation for January, the first month of the Gregorian calendar. Usually written with a capital letter and often followed by a period in formal American English.
The winter sale starts on Jan 1st.
The deadline for the project is Jan 15, so we need to finish the draft by next week.
While the full name is preferred in formal correspondence, Jan is frequently used in technical documentation and spreadsheet headers to save horizontal space.
From Old French Jehan (“John”). Doublet of John.
A clipping or hypochoristic form of Janet, Janice, Janine, Janis, etc. Doublet of Ivanka, Janelle, Janet, Janey, Janine, Jeanette, Jeanie, Jeannette, Jeannine, Jen, Jenna, Jenny, Jessie, Jo, Jody, Juanita, Shanae, Sinead, and Vanna.
From various European languages, ultimately from Latin Johannes.
Proper noun abbreviation; almost always capitalized. In British English, the period is often omitted, whereas American English typically includes it (Jan.).