What's done by accident on the other side? (6)
I believe the answer is:
beyond
'what's' is the definition.
Both the definition and answer are adverbs.
Perhaps they are linked in a way I don't understand?
'done by accident on the other side?' is the wordplay.
'done by' anagrams to 'BEYOND'.
Though, I am not sure how the anagram is indicated.
Can you help me to learn more?
(Other definitions for beyond that I've seen before include "(The) hereafter" , "unknown" , "Farther than or outside" , "Farther along in space, time or degree" , "Better than" .)