Webster's Revised Unabridged Dictionary · 1913

Tocsin

Tocsin , noun

[French, from Old French toquier to touch, French toquer (originally, a dialectic form of French toucher) + seint (for sein) a bell, Late Latin signum, from Latin signum a sign, signal. See Touch, and Sign.]

An alarm bell, or the ringing of a bell for the purpose of alarm.
The loud tocsin tolled their last alarm. — Campbell