semester

American  

[si-mes-ter] / sɪˈmɛs tər /

noun

1. (in many educational institutions) a division constituting half of the regular academic year, lasting typically from 15 to 18 weeks.

2. (in German universities) a session, lasting about six months and including periods of recess.

---

semester British  

/ sɪˈmɛstə /

noun

1. (in some universities) either of two divisions of the academic year, ranging from 15 to 18 weeks

2. (in German universities) a session of six months

---

Usage

What does semester mean? A semester is one half of an academic year. If an academic year is divided into semesters, it means it is divided into two semesters. (If the year is divided into thirds, each part is called a trimester.)Semesters are typically used in high schools and universities. In many universities, a semester lasts 15 to 18 weeks. In German universities, a semester can last up to six months. Example: I’m thinking about taking a break from school for a semester to work and save some money.

Other Word Forms

• semestral
  adjective
• semestrial
  adjective

Etymology

Origin of semester

1820–30; < German < Latin sēmē ( n ) stris of six months duration < *sex-mēnstris, equivalent to sex six + mēns ( is ) month + -tris adj. suffix (perhaps representing an earlier *mens ( i ) -teros )

Explanation

A semester is half of a school year. In September of your first year of high school, you could describe yourself as "a first-semester freshman." The noun semester comes up often when you're in high school and college. It's an easy way to divide the school year, into two equal halves, or semesters. Sometimes a class lasts for the whole year, and sometimes for just one semester. Occasionally schools split the year into three trimesters just to make things interesting. Originally, semester meant "six months," from the Latin root of the same meaning, semestris.

Example Sentences

The Tech Force program also aims to give 200 students in technology programs “meaningful public-service experience and the opportunity to earn college credits” in exchange for a volunteer Semester of Service.

From Barron's • Dec. 15, 2025

Jeff Whittall, the medical consultant for Semester at Sea, said before the ships leave port, students hear a spiel about seasickness prevention.

From Washington Post • Nov. 1, 2018

It’s what motivated Chua with Sunrise Semester to spend three hours each day attempting to reach up to 100 voters in roughly 70 homes within her assigned “turf.”

From Salon • Oct. 13, 2018

Instead, they refer students to independent, third-party operators such as the Institute for the International Education of Students, the Council on International Educational Exchange or Semester at Sea.

From Washington Times • Jul. 7, 2017

When the summer Semester came to an end, we both stayed on at Heidelberg.

From Orpheus in Mayfair and Other Stories and Sketches by Baring, Maurice