Jahr

See also: Jåhr and jähr

German

Jahr n (strong, genitive Jahres or Jahrs, plural Jahre or Jahr, diminutive Jährchen n or Jährlein n)

year (solar year, the time it takes the Earth to complete one orbit of the Sun)
Jahr für Jahr ― year after year
year (time it takes for any astronomical object to directly orbit its star)
year (period between set dates that mark a year)
Jahr und Tag
year (level or grade in school or college)

The normal plural is Jahre. The unchanged plural Jahr is rare in formal prose, but may be found in colloquial or poetic language. It is used chiefly after numerals, most often in adverbial constructions such as zwei Jahr später (“two years later”).
In colloquial German, a double plural Jahrende may be heard in the sense of “ages”, “a very long time”.

Declension of Jahr [neuter, strong]

¹Now rare, see notes.