Ranger on the rampage going around island is more upset (7)
I believe the answer is:
angrier
'more upset' is the definition.
Both the answer and definition are comparative adjectives. Perhaps there's an association between them I don't understand?
'ranger on the rampage going around island' is the wordplay.
'on the rampage' is an anagram indicator.
'going around' indicates putting letters inside.
'island' becomes 'i'.
'ranger' anagrammed gives 'angrer'.
'angrer' going around 'i' is 'ANGRIER'.
'is' is the link.
Can you help me to learn more?
(Other definitions for angrier that I've seen before include "more outraged" , "More annoyed" , "More irate" , "Not so calm" , "More worked up" .)