First-class Latin dons pass papers (8)
I believe the answer is:
splendid
'first-class' is the definition.
(I've seen this before)
'latin dons pass papers' is the wordplay.
'latin' becomes 'l'.
'dons' means one lot of letters goes inside another (don means to wear or put on).
'pass' becomes 'spend' ('spend' can be a synonym of 'pass'**).
'papers' becomes 'id' (identification papers).
'l' put into 'spend' is 'splend'.
'splend'+'id'='SPLENDID'
(Other definitions for splendid that I've seen before include "Excellent, first-class" , "Noble" , "Great" , "Marvellous" , "Characterised by grandeur" .)