Without principal, there's some chaos (7)
I believe the answer is:
anarchy
'some chaos' is the definition.
(I've seen this in another clue)
'without principal there's' is the wordplay.
'without' means one lot of letters goes inside another.
'principal' becomes 'arch' (as in arch-enemy).
'there's' becomes 'any' (I am not sure about this - if you are sure you should believe this answer much more).
'arch' going within 'any' is 'ANARCHY'.
Can you help me to learn more?
(Other definitions for anarchy that I've seen before include "without structure" , "Complete absence of law" , "Uncontrolled disorder" , "Chaotic state" , "General disorder" .)