Drop Laurence Olivier's initials onto graduate certificate (7)
I believe the answer is:
diploma
'certificate' is the definition.
(academic certificate)
'drop laurence olivier's initials onto graduate' is the wordplay.
'drop' becomes 'dip' (I've seen this before).
'initials' indicates taking the first letters.
'onto' is a charade indicator (letters next to each other).
'graduate' becomes 'MA' (abbreviation for Master of Arts).
The first letters of 'laurence olivier' is 'lo'.
'dip'+'lo'+'ma'='DIPLOMA'
(Other definitions for diploma that I've seen before include "Document conferring honour" , "Course certificate" , "Certificate awarded by college for educational attainment" , "Certificate of education" , "Certificate of competency" .)