Alarm
An Alarm in Freemasonry means "a notice of the approach of someone desiring admission," given by the tyler by three distinct knocks on the door. A knock at the Lodge door is so named because it calls for alertness, lest the wrong man be permitted to enter.
See also definition in Masonicdictionary
~~ooOoo~~
This page is adapted from the Glossary at Phoenixmasonry — Used with permission.