a document given by an educational institution conferring a degree on a person or certifying that the person has satisfactorily completed a course of study.

a document conferring some honor, privilege, or power.

a public or official document, esp. one of historical interest

a diploma from Carolingian times.

to grant or award a diploma to.

noun

authority , award , charter , commission , confirmation , credentials , degree , honor , recognition , sheepskin , shingle , voucher , warrant , certificate , document