n. 警钟, 警报

Tocsin \Toc"sin\, n. [F., fr. OF. toquier to touch, F. toquer
(originally, a dialectic form of F. toucher) + seint (for
sein) a bell, LL. signum, fr. L. 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.