Outrageous isolation, no law left or act to make it illegal (15)

'outrageous isolation' is the definition.
The definition suggests a singular noun which matches the answer.

'no law left or act to make it illegal' is the wordplay.
I cannot really see how this works, but
'no' could be 'o' (resembles 0 - 'no' can mean 'zero') and 'o' is found in the answer.
'left' could be 'al' (I've seen this in other clues) and 'al' is present in the answer.
'it' could be 'sa' (old-fashioned abbreviation for sex appeal) and 'sa' is present in the answer.
This may be the basis of clue (or it may be nonsense).

Can you help me to learn more?