A Tocsin is an alarm or other signal sounded by a bell or bells. It may refer to:
Cold War TOCSIN, the codeword attached by the Royal Observer Corps to any reading on the Bomb Power Indicator or the Atomic Weapons Detection Recognition and Estimation of Yield (AWDREY) system after a nuclear strike on the United Kingdom during the Cold War Exercise Tocsin, a name for the nuclear attack simulation performed by the Government of Canada Tocsin, a Harvard undergraduate group against nuclear weapons and by 1963 also against the Vietnam War, led by Todd Gitlin
Music Tocsin (album), a 1984 album by gothic rock band Xmal Deutschland Tocsin, a 2013 album by French shoegaze band Year of No Light the fourth and final movement of the Symphony No. 11 (1957) by Dmitri Shostakovich
Newspapers The Tocsin, an early Australian socialist newspaper Tocsin, a newspaper from Red Bluff, California; see California Digital Newspaper Collection Marin County Tocsin, a newspaper from Marin County, California; see California Digital Newspaper Collection Tehama Tocsin, an early name of the Chico Enterprise-Record newspaper in Tehama, California Tocsin News, or The Enterprise-Tocsin, a newspaper in Mississippi The Tocsin of Liberty, an anti-slavery newspaper from the Liberty Party (United States, 1840)
Other Tocsin, Indiana, a small town in the United States "The Tocsin", a poem by John Pierpont
See also