IPA: //nɒn.rɪˈstrɪk.tɪv//
KK: /nɑnˈrɪstrɪktɪv/
This word describes something that does not limit or restrict the meaning of what it modifies, often used in grammar to refer to clauses that add extra information without changing the main point.
The book, which was published last year, is a nonrestrictive clause that adds information about the title.
Nonrestrictive → It is formed from "non-" (meaning not) and "restrict" (from Latin "restringere", meaning to bind back or limit) and the suffix "-ive" (meaning having the nature of). The word "nonrestrictive" means not having the nature of limiting or binding back, often used in grammar to describe clauses that add information without limiting the meaning of the sentence.
Think of 'not' ('non-') limiting or 'binding back' ('restringere') something — that's why nonrestrictive means it doesn't limit the information.