[yeer] 
| 1. | a period of 365 or 366 days, in the Gregorian calendar, divided into 12 calendar months, now reckoned as beginning Jan. 1 and ending Dec. 31 (calendar year or civil year). Compare common year, leap year. |
| 2. | a period of approximately the same length in other calendars. |
| 3. | a space of 12 calendar months calculated from any point: This should have been finished a year ago. |
| 4. | Astronomy.
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| 5. | the time in which any planet completes a revolution round the sun: the Martian year. |
| 6. | a full round of the seasons. |
| 7. | a period out of every 12 months, devoted to a certain pursuit, activity, or the like: the academic year. |
| 8. | years,
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| 9. | a group of students entering school or college, graduating, or expecting to graduate in the same year; class. |
| 10. | a year and a day, a period specified as the limit of time in various legal matters, as in determining a right or a liability, to allow for a full year by any way of counting. |
| 11. | from the year one, for a very long time; as long as anyone remembers: He's been with the company from the year one. |
| 12. | year in and year out, regularly through the years; continually: Year in and year out they went to Florida for the winter. Also, year in, year out. |
rā season, part of a day, hour| sidereal year n. The time required for one complete revolution of the earth about the sun, relative to the fixed stars, or 365 days, 6 hours, 9 minutes, 9.54 seconds in units of mean solar time. |