The noun year has 4 senses (first 4 from tagged texts)
1. (832) year, twelvemonth, yr -- (a period of time containing 365 (or 366) days; "she is 4 years old"; "in the year 1920")
2. (27) year -- (a period of time occupying a regular part of a calendar year that is used for some particular activity; "a school year")
3. (5) year -- (the period of time that it takes for a planet (as, e.g., Earth or Mars) to make a complete revolution around the sun; "a Martian year takes 687 of our days")
4. (1) class, year -- (a body of students who graduate together; "the class of '97"; "she was in my year at Hoehandle High")