Chaos when idiot takes Times (5)
I believe the answer is:
abyss
'chaos' is the definition.
(I have seen 'Primal chaos ' mean 'abyss' so perhaps 'chaos' could also mean 'abyss')
'idiot takes times' is the wordplay.
'idiot' becomes 'ass' (I've seen this before).
'takes' means one lot of letters goes inside another.
'times' becomes 'by' (I've seen this in other clues).
'ass' enclosing 'by' is 'ABYSS'.
'when' acts as a link.
(Other definitions for abyss that I've seen before include "gaping hole" , "something rather deep" , "Fathomless pit" , "depths of sea" , "canyon?" .)