To be ill can be against the law (5)
I believe the answer is:
libel
'to be ill can be against the law' is the definition.
I can't judge whether this defines the answer.
'to be ill can be' is the wordplay.
'can be' indicates an anagram.
'be'+'ill'='beill'
'beill' is an anagram of 'LIBEL'.
Can you help me to learn more?
(Other definitions for libel that I've seen before include "Written defamation" , "Offence" , "Defame falsely" , "Crime of publishing false statement that damages reputation" , "Write ill of" .)