Wandering in the gallery can mean trouble! (7)
I believe the answer is:
allergy
'mean trouble' is the definition.
The answer and definition can be both states of affairs as well as being singular nouns.
Maybe you can see an association between them that I don't see?
'wandering in the gallery' is the wordplay.
'wandering in' indicates an anagram (I've seen this in other clues).
'gallery' anagrammed gives 'ALLERGY'.
'can' acts as a link.
Can you help me to learn more?
(Other definitions for allergy that I've seen before include "Largely to do with adverse reaction" , "Susceptibility" , "Abnormal sensitivity to a food" , "Hypersensitive reaction of the body to a foreign substance" , "Hypersensitive reaction to certain substances" .)