(hydrology) The timespan between October 1 and September 30 of the next year, differing from the calendar year because part of the precipitation that falls in late autumn and winter accumulates as snow and does not drain until the following spring or summer.

plural of lunar year

(literary) The later years of one's life, especially after one has finished one's career.

plural of academic year

(informal, slang, Canada, US) an exclamation of excitement or joy

(colloquial) Yes; an expression of affirmation.

plural of year to date

An informal competition among birdwatchers to determine who can see or hear the largest number of species of birds within a single calendar year and within a specific geographical area.

The holiday commemorating (the beginning of) the new year.

A year that does not contain the day February 29.