(Canada, US,dated) A simple wind instrument, such as a kazoo or tin horn.
1894, “Splendid work of the National Association of Dental Faculties”, in Dominion Dental Journal, volume VI, page 221:
It goes against the grain to toot one’s own “bazoo”
2012, Sharon Davis, Every Chart Topper Tells a Story:
Born Charles Westover in Coopersville, Michigan, on 30 December 1939, he learned to play the bazoo, ukulele and, eventually, the guitar.
2017 May 1, Peter Jensen Brown, quoting Leavenworth Weekly Times, July 21, 1870, “Bazoo, Kazoo, Bazooka”, in Early Sports and Pop Culture History Blog: