major
n. countablen. the main subject you choose to study at a university or college. You spend most of your time on this subject to get your degree.
n. the principal field of study chosen by a student in an undergraduate degree program. Often used to refer to the student themselves in relation to their subject.
She decided to change her major from history to biology.
After completing his general education requirements, he declared a major in computer science to focus on software engineering.
The university requires all students to complete a capstone project within their chosen major before they are eligible for graduation.
Commonly used with the preposition 'in' to specify the field of study.
I am studying a major of chemistryI am a chemistry majorIn English, you usually say you have a major 'in' a subject or that you are a '[Subject] major' rather than using 'of'.