A graduate joins true sort of dilettante (7)
I believe the answer is:
amateur
'dilettante' is the definition.
(I've seen this before)
'a graduate joins true sort' is the wordplay.
'graduate' becomes 'ma' (abbreviation for Master of Arts).
'joins' says to put letters next to each other.
'sort' indicates anagramming the letters.
'true' anagrammed gives 'teur'.
'a'+'ma'+'teur'='AMATEUR'
'of' acts as a link.
(Other definitions for amateur that I've seen before include "Ham" , "he's not making any money" , "Unpaid (sports)" , "Not pro" , "Fancier" .)