Explain trophy inscribed with name of tragic king (5,2)
I believe the answer is:
clear up
'explain' is the definition.
(clearing up is a kind of explaining)
'trophy inscribed with name of tragic king' is the wordplay.
'trophy' becomes 'cup' (cup is a kind of trophy).
'inscribed with' is an insertion indicator (I've seen this in other clues).
'name of tragic king' becomes 'Lear' (King Lear).
'cup' placed around 'lear' is 'CLEAR-UP'.
(Other definitions for clear up that I've seen before include "Sort out" , "how conditions may improve" , "iron out" , "be less untidy" , "(Of bad weather) improve" .)