National Isolation, Exclusion Of Foreigners
noun, verbal noun
A country in chains is under a national isolation policy. They're bound and they can't visit anywhere else.
さこく
This is a jukugo word that uses the on'yomi readings of the kanji. You should be able to read this on your own.
日本が鎖国していたのはいつですか。
When was Japan in national isolation?