To stay free after starting trouble is very nice! (5)
I believe the answer is:
tasty
'nice' is the definition.
(thesaurus)
'to stay free after starting trouble is very' is the wordplay.
I cannot really understand how this works, but
an anagram of 'stay' is 'asty' which is within the answer.
A single letter 't' remains which might be clued in a way I don't see.
This may be the basis of the clue (or it may be nonsense).
Can you help me to learn more?
(Other definitions for tasty that I've seen before include "Attractive, appealing" , "Toothsome" , "Like nice grub" , "Appetising, having pleasant flavour" , "Savoury" .)