Slavery unlikely to be found around Croatia (6)
I believe the answer is:
Here is my best explanation:
'slavery' is the definition.
'unlikely to be found around croatia' is the wordplay.
'unlikely' becomes 'tall' (I've seen this before).
'to be found around' means one lot of letters goes inside another.
'croatia' becomes 'hr' (I can't justify this - if you can you should give a lot more credence to this answer).
'tall' enclosing 'hr' is 'THRALL'.