cap and gown

noun

1. a ceremonial mortarboard and gown worn by faculty, students, etc., as at commencement.

Word History and Origins

Origin of cap and gown¹

First recorded in 1855–60

Idioms and Phrases

Ceremonial dress worn at graduation exercises; by extension, the academic community (also see town and gown. For example, Mary was very proud) when she received her cap and gown for commencement. [Mid-1800s]