Yen is accepted by Netherlands, informally, in periodically cut-off community (4,6)
I believe the answer is:
holy island
'informally in periodically cut-off community' is the definition.
I can't judge whether this definition defines the answer.
'yen is accepted by netherlands' is the wordplay.
'yen' becomes 'y' (resembles the symbol for the currency of Japan).
'accepted by' means one lot of letters goes inside another (inserted letters are accepted).
'netherlands' becomes 'Holland' (synonyms).
'y'+'is'='yis'
'yis' inserted into 'holland' is 'HOLY ISLAND'.
Can you help me to learn more?
(Another definition for holy island that I've seen is " Lindisfarne".)