Utter chaos at the end, before climax (5)
I believe the answer is:
speak
'utter chaos' is the definition.
'speak' can be an answer for 'utter' (synonyms). I am unsure of the 'chaos' bit.
'at the end before climax' is the wordplay.
'at' means one lot of letters go next to another.
'the end before' becomes 's' (I can't explain this - if you can you should believe this answer much more).
'climax' becomes 'peak' (I've seen this in another clue).
's'+'peak' is 'SPEAK'.
Can you help me to learn more?
(Other definitions for speak that I've seen before include "Converse" , "Utter words" , "Say something" , "Orate" , "express" .)