Fuddled spy is upset with it (5)
I believe the answer is:
tipsy
'fuddled' is the definition.
(synonyms)
'spy is upset with it' is the wordplay.
'is upset with' indicates an anagram (I've seen 'are upset' mean this).
'spy' with its letters anagrammed with 'it' can make 'TIPSY'.
(Other definitions for tipsy that I've seen before include "Inebriated" , "Slightly drunk" , "1 over 8" , "Merry, squiffy" , "Slightly intoxicated" .)