Graduate school
The term "graduate school" could be confusing because the verb "graduate" is also used to mean completing high school education or earning a Bachelor's degree. The verb is used for all those types of schools, but the meaning of the adjective "graduate" is changed to mean "postgraduate" in the term "graduate school". The small change in meaning can be viewed with an air of sophistication, where experienced students are often more aware of the issue, while novice students might not be aware, as being more naive.