Briton given master's degree -- lucky thing? (6)
I believe the answer is:
mascot
'lucky thing?' is the definition.
(I've seen this before)
'briton given master's degree' is the wordplay.
'briton' becomes 'Scot' (Scot is a type of Briton).
'given' says to put letters next to each other.
'master's degree' becomes 'MA' (MA is an example).
'scot' after 'ma' is 'MASCOT'.
(Other definitions for mascot that I've seen before include "Symbolic figure, for a team say" , "Character or object used to bring good luck, or represent an organisation" , "Thing supposed to bring good luck" , "Thing believed to bring good luck, perhaps to team" , "Symbolic figure, of a team perhaps" .)