Aids illegally (5)
I believe the answer is:
abets
'aids illegally' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for abets that I've seen before include "Aids in wrong-doing" , "Helps (someone to commit crime)" , "Aids and encourages" , "Assists or encourages" , "Assists in wrongdoing" .)