Buchan play biographical name Buch·an \ˈbə-kən, -ḵən\ Definition of Buchan Sir John 1875–1940 1st Baron Tweeds*muir play \ˈtwēdz-ˌmyu̇r\ Scot. author; gov.-gen. of Canada (1935–40) Writing? Check your grammar now! Seen and Heard What made you want to look up Buchan? Please tell us where you read or heard it (including the quote, if possible).