Definition of "tick" []

• A light, sharp, clicking sound made repeatedly by a machine, such as a clock. (noun)
• Chiefly British A moment. (noun)
• A light mark used to check off or call attention to an item. (noun)
• Informal A unit on a scale; a degree: when interest rates move up a tick. (noun)
• To emit recurring clicking sounds: as the clock ticked. (verb-intransitive)

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.

• "The house rang with the wreak and wrack of wood, and that _tick tick tick_ of the heating system."
• "Every creature on the planet has it's place in nature, but the tick is an abomination."
• "Alas, the mystery of what makes people tick is inherently difficult to investigate in a test tube."