Singer partly prone to getting upset (5)
I believe the answer is:
tenor
'singer' is the definition.
(I know that tenor is a type of singer)
'partly prone to getting upset' is the wordplay.
'partly' indicates a hidden word (part of the clue is used).
'getting upset' is a reversal indicator.
'ronet' is hidden within 'prone to'.
'ronet' reversed gives 'TENOR'.
(Other definitions for tenor that I've seen before include "Singer (one of three?)" , "thread" , "character" , "Male voice of high pitch, like Luciano" , "Voice of Tamino" .)