Rosh is the Hebrew word for “head”, ha is the definite article (“the”), and shana means year. Thus Rosh HaShanah means “start of the year”, referring to the Jewish day of new year.[3][4]
The term Rosh Hashanah in its current meaning does not appear in the Torah. Leviticus 23:24[5] refers to the festival of the first day of the seventh month as zikhron teru’ah (“a memorial of blowing [of horns]”); it is also referred to in the same part of Leviticus as ‘שַׁבַּת שַׁבָּתוֹן’ (shabbat shabbaton) or ultimate Sabbath or meditative rest day, and a “holy day to God”. These same words are commonly used in the Psalms to refer to the anointed days. Numbers 29:1[6] calls the festival yom teru’ah (“day of blowing [the horn]”).
The term rosh hashanah appears once in the Bible (Ezekiel 40:1),[7] where it has a different meaning: either generally the time of the “beginning of the year”, or possibly a reference to Yom Kippur,[8] or to the month of Nisan.[a][12]
In the Jewish prayer-books (the Siddur and Machzor), Rosh Hashanah is also called Yom Hazikaron (the day of remembrance),[4] not to be confused with the modern Israeli remembrance day of the same name.
Rosh Hashanah marks the start of a new year in the Hebrew calendar (one of four “new year” observances that define various legal “years” for different purposes as explained in the Mishnah and Talmud).[4] It is the new year for people, animals, and legal contracts. The Mishnah also sets this day aside as the new year for calculating calendar years, shmita years, and yovel years. Rosh Hashanah commemorates the creation of Man.[13]
https://en.wikipedia.org/wiki/Rosh_Hashanah
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