"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.