Where Leslie gets upset about Victor (7)
I believe the answer is:
seville
'where' is the definition.
The answer is a location as well as being a singular noun. This is suggested by the definition.
'leslie gets upset about victor' is the wordplay.
'gets upset' indicates anagramming the letters (I've seen 'getting upset' mean this).
'about' means one lot of letters goes inside another.
'victor' becomes 'V' (phonetic alphabet: alpha, bravo, charlie etc.).
'leslie' with letters rearranged gives 'seille'.
'seille' going around 'v' is 'SEVILLE'.
Can you help me to learn more?
(Other definitions for seville that I've seen before include "Spanish port" , "Spanish tourist centre" , "Fruit for marmalade" , "Spanish city; orange type" , "Rossini opera 'The Barber of ....'" .)