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.

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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

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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

This time along with Rossen Ventzislavov, an educator who brought me out to Woodbury University last spring as a fellow to teach a one-of-a-kind semester on Black modernism in architecture, design and popular culture.

From Los Angeles Times • Apr. 13, 2026

My dad said, `No, Mr. Wahl, I’ve got to pay $855.53 for that boy’s semester.’

From Los Angeles Times • Apr. 12, 2026

To find their way into Cynthia’s unwieldy case at the start of the fall 2025 semester, Concannon and her teammates tackled the project much like a task force would, dividing it into sections.

From Slate • Apr. 6, 2026

After finishing the fall semester of his sophomore year, Bior returned to Uganda for winter break.

From The Wall Street Journal • Mar. 25, 2026

By the time the fall semester officially began two days later, I had promised myself to forget Danny as quickly as possible.

From "The Chosen" by Chaim Potok