A ring binder is a file with hard covers, which you can insert pages into. The pages are held in by metal rings on a bar attached to the inside of the file.
ring binder in British English
noun
a loose-leaf binder fitted with metal rings that can be opened to allow perforated paper to be inserted
In other languages
ring binder
British English: ring binder /rɪŋ ˈbaɪndə/ NOUN
A ring binder is a file with hard covers, which you can insert pages into. The pages are held in by metal rings on a bar attached to the inside of the file.