1. Sudden fear or concern caused by the realization of danger or an impending setback. See Synonyms at fear.
2. A warning of existing or approaching danger: The committee's report issued an alarm about the dangerous condition of the town's buildings.
3. A device that is used to warn of danger by means of a sound or signal: a fire alarm.
4. The sounding mechanism of an alarm clock: The alarm went off at 6:30.
5. A call to arms.
tr.v. a·larmed, a·larm·ing, a·larms
1. To fill with alarm or anxious concern. See Synonyms at frighten.
2. To give warning to: "The soldiers ... killed every dog within three miles to prevent a bark that would alarm the enemy" (William Least Heat-Moon).
3. To equip with or protect by an alarm: The dormitory doors are alarmed from 7:00 PM to 7:00 AM.
[Middle English, from Old French alarme, from Old Italian allarme, from all'arme, to arms : alla, to the (from Latin ad illa : ad, to; see AD- + illa, neuter pl. of ille, that, the; see al-1 in the Appendix of Indo-European roots) + arme, arms (from Latin arma; see ar- in the Appendix of Indo-European roots).]
The American Heritage® Dictionary of the English Language, Fifth Edition copyright ©2022 by HarperCollins Publishers. All rights reserved.
Indo-European & Semitic Roots Appendices
Thousands of entries in the dictionary include etymologies that trace their origins back to reconstructed proto-languages. You can obtain more information about these forms in our online appendices:
The Indo-European appendix covers nearly half of the Indo-European roots that have left their mark on English words. A more complete treatment of Indo-European roots and the English words derived from them is available in our Dictionary of Indo-European Roots.