alarum-bell, 'larum-bell (n.)
Alarum Bell, Larum-Bell
[King Henry IV alone, as if to sleep] why ... leavest the kingly couch / A watch-case, or a common 'larum-bell?
[Macduff to all] Ring the alarum-bell! Murder and treason!
[Macbeth to all] Ring the alarum bell!
SHAKESPEARE'S WORDS © 2018 DAVID CRYSTAL & BEN CRYSTAL