Scholars of 50 briefly repeating themselves? Not on! (8)
I believe the answer is:
literati
'scholars' is the definition.
(I've seen this before)
'50 briefly repeating themselves? not on' is the wordplay.
'50 briefly' becomes 'L' (Roman numeral).
'repeating themselves?' becomes 'iteration' (iteration means repeating something).
'not' is a deletion indicator.
'iteration' with 'on' removed is 'iterati'.
'l'+'iterati'='LITERATI'
'of' acts as a link.
(Other definitions for literati that I've seen before include "scholars" , "Men and women of letters" , "Bookish types" , "Learned folk" , "Well-read and scholarly people" .)