Added 9 October 2026 muir noun Categories: PeopleRare Words noun ! Definition from WordNet 3.1, Princeton University. More about muir at Wordnik → Where our words come from → United States naturalist (born in England) who advocated the creation of national parks (1838-1914). Related Words: moyermoirsheriffannualtorrepassybogheathlandheathmoorlandmoorbogland Back to today's word