tocsin Look up tocsin at Dictionary.com
"alarm bell," 1586, from M.Fr. toquassen "an alarm bell, the ringing of an alarm bell" (1372), from O.Prov. tocasenh, from tocar "to strike" (from V.L. *toccare "strike a bell;" see touch) + senh "bell, bell note," from L.L. signum "bell, ringing of a bell," in L. "mark, signal." The current Eng. spelling is from 1794, adopted from modern Fr.