Definition of "alarm clock" [alarm clock]

• A clock that can be set to sound a bell or buzzer at a desired hour. (noun)

American Heritage(R) Dictionary of the English Language, Fifth Edition. Copyright (c) 2011 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.

• "Reaching out, she picked up the small, gold-cased alarm clock sitting on the coffee table to check the time."
• "My alarm clock didn't go off this morning, instead I woke up to the sound of my cell phone ringing, it was my daughter Kirstin calling to say "Happy Mother's Day"."
• "The alarm clock sounds as usual at six A.M. Jill had automatically set it the night before."