Idiom of the day :- A back number

Usage, examples and definition of the Idiom :-

An outdated newspaper or periodical is a back number. ‘I’m researching back number newspapers for an article I’m writing.’ the reporter said. A person is a back number when he has lost his influence or his thinking is considered old-fashioned. ‘No one seeks my opinion anymore,’ Neil sighed. ‘I feel like a back number in this office.’