Positive sign in nonsense supplied by university beset by defeat (6-2)
I believe the answer is:
thumbs-up
'positive sign' is the definition.
(I've seen this before)
'nonsense supplied by university beset by defeat' is the wordplay.
'nonsense' becomes 'BS' (bullsh*t).
'supplied by' is a charade indicator (letters next to each other).
'university' becomes 'U' (abbreviation for university).
'beset by' indicates putting letters inside ('beset' could historically mean 'cover').
'defeat' becomes 'thump' (I can't explain this - if you can you should give a lot more credence to this answer).
'bs'+'u'='bsu'
'bsu' going into 'thump' is 'THUMBS-UP'.
'in' is the link.
Can you help me to learn more?
(Other definitions for thumbs-up that I've seen before include "Elevated digits as sign of approval" , "Elevation of thick fingers as sign of approval" , "Green light" , "Indication of approval" , "Positive sign" .)