tracer

noun

trac·​er ˈtrā-sər How to pronounce tracer (audio)
1
: one that traces, tracks down, or searches out: such as
a
: a person who traces missing persons or property and especially goods lost in transit
b
: an inquiry sent out in tracing a shipment lost in transit
2
: one who traces designs, patterns, or markings
3
: a device (such as a stylus) used in tracing
4
a
: ammunition containing a chemical composition to mark the flight of projectiles by a trail of smoke or light
b
: a substance used to trace the course of a chemical or biological process
especially : label sense 1d

Examples of tracer in a Sentence

The enemy fired tracers at the aircraft carrier. They injected her with a radioactive tracer and tracked it via X-rays.
Recent Examples on the Web Video filmed by Al Jazeera, at an unknown time, shows people scrambling over a berm to get away from gunfire as red tracer rounds light up the sky. Jonathan Baran, Washington Post, 1 Mar. 2024 This chemistry gives the molten rock a unique chemical fingerprint that can act like a tracer. Maya Wei-Haas, Smithsonian Magazine, 21 Feb. 2024 More obscure causes include overheating electrical cattle fences, tracer bullets fired by gun enthusiasts and sunlight focused through broken glass. John Riha, Discover Magazine, 12 Nov. 2023 Several illumination flares were seen floating down in the distance while red tracer rounds were accompanied by the sound of heavy machine gun fire. Rhea Mogul, CNN, 20 Oct. 2023 Each bag also comes with a latch lock and has a Tumi tracer, a unique serial number that helps reunite travelers with their lost or stolen items. Paris Wilson, Condé Nast Traveler, 8 Sep. 2023 To study the weathering of organic carbon in rocks, the team used a tracer element called rhenium. Laura Baisas, Popular Science, 5 Oct. 2023 In fact, scientists have been doing studies like this since the 1960s, releasing tracers such as zinc sulfide powder or sulfur hexafluoride gas into the stratosphere to study air currents. Douglas Fox, Scientific American, 19 Sep. 2023 Ricardo Cooper, who lives in Washington, D.C., helps run a nonprofit and works as a pandemic contact tracer for the District of Columbia. New York Times, 4 Mar. 2022

These examples are programmatically compiled from various online sources to illustrate current usage of the word 'tracer.' Any opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback about these examples.

Word History

First Known Use

14th century, in the meaning defined at sense 1

Time Traveler
The first known use of tracer was in the 14th century

Dictionary Entries Near tracer

Cite this Entry

“Tracer.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/tracer. Accessed 19 Mar. 2024.

Kids Definition

tracer

noun
trac·​er ˈtrā-sər How to pronounce tracer (audio)
1
a
: a person who traces missing persons or property
b
: an inquiry sent out in tracing a shipment lost in transit
2
a
: ammunition containing a chemical composition to mark the flight of projectiles by a trail of smoke or fire
b
: a substance and especially a labeled element or atom used to trace the course of a chemical or biological process

Medical Definition

tracer

noun
trac·​er ˈtrā-sər How to pronounce tracer (audio)
: a substance used to trace the course of a process
specifically : a labeled element or atom that can be traced throughout chemical or biological processes by its radioactivity or its unusual isotopic mass

More from Merriam-Webster on tracer

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