noun, noun or participle which takes 'suru', transitive verb, noun which may take the genitive case particle 'no'
major; specialization; field of study
Refers to a student's main academic subject at university or a researcher's specialized field. Used as a noun, with する to mean 'to major in', and as a no-adjective.
大学では経済学を専攻しています。
I am majoring in economics at university.
His major is physics.
専攻科目を選ぶのに悩んでいる。
I'm having trouble choosing my major subject.