Of the age of one year.

(astronomy) the time it takes for the Solar System to orbit around the center of the Milky Way Galaxy, estimated to be from 225 to 250 million years.

Alternative spelling of yearbook

(astronomy) The span of time between successive heliacal risings of the star Sirius, equivalent to almost precisely 365¼ days.

solar year

A year of rest for the land observed every seven years in ancient Judea, which included allowing the fields to lie without tilling, sowing, or reaping from one autumn to the next in accordance with a Levitical commandment.

(law) A year in the reign of a monarch, beginning on the day of accession, the set of which are numbered ordinally. Formerly laws in the United Kingdom were identified in part by the regnal year of the monarch, and this practice is still followed in some Commonwealth countries.

Alternative form of yesteryear

(informal) A regular calendar year, as opposed to a dog year or the "year" of any other animal species.

Alternative spelling of yearlong.