It's chaotic from Roman Catholic, as usual (6)
I believe the answer is:
normal
'as usual' is the definition.
(I've seen this before)
'it's chaotic from roman catholic' is the wordplay.
I cannot quite see how this works, but
an anagram of 'roman' is 'norma' which is within the answer.
A single letter 'l' remains which might be clued in a way I don't see.
This explanation may well be incorrect...
Can you help me to learn more?
(Other definitions for normal that I've seen before include "Conforming to what is usual" , "Accustomed" , "Standard, expected" , "Usual; at right angles" , "Unexceptional" .)