Busy period in pirates' domain, with no going back (4,6)
I believe the answer is:
high season
'busy period' is the definition.
The definition suggests a singular noun which matches the answer.
'pirates' domain with no going back' is the wordplay.
'pirates' domain' becomes 'highseas' (I can't justify this - if you can you should give a lot more credence to this answer).
'with' means one lot of letters go next to another.
'going back' says the letters should be written in reverse.
'no' reversed gives 'on'.
'highseas'+'on'='HIGH SEASON'
'in' is the link.
Can you help me to learn more?
(Another definition for high season that I've seen is " peak tourist period".)