1.Definition: narrowly restricted in outlook or scope

"Insular attitudes toward foreigners"

Related Adjective(s):parochial

2.Definition: relating to or characteristic of or situated on an island

"Insular territories", "Hawaii's insular culture"

3.Definition: suggestive of the isolated life of an island

"An exceedingly insular man; so deeply private as to seem inaccessible to the scrutiny of a novelist"