IPA: /ʌnˈnʌmbəd/
KK: /ʌnˈnʌmbərd/
Not having a specific number assigned to it, often used to describe things that cannot be counted or are not labeled with numbers.
The book had several unnumbered pages at the beginning.
Unnumbered → It is formed from "un-" (meaning not) and "number" (from Old French *nombre*, meaning a numeral or quantity). The word "unnumbered" means not assigned a number or lacking a numerical designation.
Think of 'not' ('un-') having a 'number' — that's why unnumbered means something that does not have a number.