Definition of "back-number" []

• Someone who is no longer popular (noun)

WordNet. Princeton University. 2010.

• "What you quote, however, about your own frame of mind is obviously a back-number…."
• "So I went further, pointing out that the Yenbo-Medina sector also became a back-number; and advised the transfer to Akaba of the stores, money, and officers now devoted to Ali and Abdulla."
• "He smiled wanly and asked for his mail, which consisted only of a pile of back-number copies of a newspaper."