Man pages matching name umount2 in section 2:

umount2.2.en	debian 10 / manpages-dev
umount2.2.es	debian 10 / manpages-es
umount2.2.it	debian 10 / manpages-it
umount2.2.ja	debian 10 / manpages-ja-dev
umount2.2.en	debian 11 / manpages-dev
umount2.2.fr	debian 11 / manpages-fr-dev
umount2.2.it	debian 11 / manpages-it-dev
umount2.2.ja	debian 11 / manpages-ja-dev
umount2.2.en	debian 12 / manpages-dev
umount2.2.fr	debian 12 / manpages-fr-dev
umount2.2.it	debian 12 / manpages-it-dev
umount2.2.ja	debian 12 / manpages-ja-dev
umount2.2.ru	debian 12 / manpages-ru-dev
umount2.2.uk	debian 12 / manpages-uk-dev