Nautical order to stop a tax on goods round the south (5)
I believe the answer is:
avast
'goods round the south' is the definition.
I can't tell whether this defines the answer.
'nautical order to stop a tax' is the wordplay.
'nautical order' becomes 's' (I can't explain this - if you can you should believe this answer much more).
'to stop' indicates putting letters inside (inserted letters plug or stop a gap).
'tax' becomes 'vat' (British sales tax).
'a'+'vat'='avat'
's' put within 'avat' is 'AVAST'.
'on' is the link.
Can you help me to learn more?
(Other definitions for avast that I've seen before include "Stop! (naut.)" , "eleven [CEASE] at sea" , "Stop (nautical)" , "Stop, nautically speaking" , "order for tar" .)