year

American Heritage® Dictionary of the English Language, Fourth Edition

1. n. The period of time during which Earth completes a single revolution around the sun, consisting of 365 days, 5 hours, 49 minutes, and 12 seconds of mean solar time. In the Gregorian calendar the year begins on January 1 and ends on December 31 and is divided into 12 months, 52 weeks, and 365 or 366 days. Also called calendar year.
2. n. A period approximately equal to a year in other calendars.
3. n. A period of approximately the duration of a calendar year: We were married a year ago.
4. n. A sidereal year.
5. n. A solar year.
6. n. A period equal to the calendar year but beginning on a different date: a tax-reckoning year; a farming year.
7. n. A specific period of time, usually shorter than 12 months, devoted to a special activity: the academic year.
8. n. Age, especially old age: I'm feeling my years.
9. n. An indefinitely long period of time: it's been years since we saw her.

Century Dictionary and Cyclopedia

1. n. A full round of the seasons; the period of the earth's revolution round the sun; more accurately, the interval between one vernal equinox and the next, or one complete mean apparent circuit of the ecliptic by the sun, or mean motion through 360° of longitude. This is specifically the tropical year, which determines the sequence of the seasons (sometimes also called the astronomical or solar year). Its length is about 365 days, 5 hours, 48 minutes, 46 seconds. Owing to the precession of the equinoxes, this is less than the length of the sidereal year, the true period of the sun's revolution, or his return to the same place in relation to the fixed stars, which is 365 days, 6 hours, 9 minutes, 9.3 seconds. See also style, n., 9. Abbreviated y., yr.
2. n. The time in which any planet completes a revolution round the sun: as, the year of Jupiter or of Saturn.
3. n. A space of about 365 days, used in the civil or religious reckoning of time; especially, the usual period of 365 or 366 days, divided into twelve calendar months, now reckoned as beginning with the 1st of January and ending with the 31st of December: as, the year 1891 (see legal year, below); also, a period of approximately the same length in other calendars. Compare calendar.
4. n. A space of twelve calendar months without regard to the point from which they are reckoned: as, he sailed on June 1st, and was absent just one year.
5. n. plural Period of life; age: as, he is very vigorous for his years: often used specifically to note old age. See in years, below.
6. n. The older plural year still remains in popular language: as, the horse is ten year old.
7. n. Incorrectly, a year of the Julian calendar.
8. n. part of the sovereign's prerogative in England, whereby he was entitled to the profits for a year and a day of the lands held by persons attainted of petty treason or felony, together with the right of wasting them, afterward restoring them to the lord of the fee. It was abolished by the Felony Act, 1870.

Wiktionary

1. n. The time it takes the Earth to complete one revolution of the Sun (between 365.24 and 365.26 days depending on the point of reference).
2. n. by extension The time it takes for any planetary body to make one revolution around another body.
3. n. A period between set dates that mark a year, from January 1 to December 31 by the Gregorian calendar.
4. n. A scheduled part of a calendar year spent in a specific activity.
5. n. sciences A Julian year, exactly 365.25 days, represented by "a".
6. n. A level or grade in school or college.

GNU Webster's 1913

1. n. The time of the apparent revolution of the sun trough the ecliptic; the period occupied by the earth in making its revolution around the sun, called the astronomical year; also, a period more or less nearly agreeing with this, adopted by various nations as a measure of time, and called the civil year.
2. n. The time in which any planet completes a revolution about the sun.
3. n. Age, or old age.

WordNet 3.0

1. n. a period of time occupying a regular part of a calendar year that is used for some particular activity
2. n. a period of time containing 365 (or 366) days
3. n. the period of time that it takes for a planet (as, e.g., Earth or Mars) to make a complete revolution around the sun
4. n. a body of students who graduate together