tracer

[trey-ser]

noun

1. a person or thing that traces. trace.

2. a person whose business or work is the tracing tracing trace of missing property, parcels, persons, etc.

3. an inquiry sent from point to point to trace a missing shipment, parcel, or the like, as in a transportation system.

4. any of various devices for tracing tracing trace drawings, plans, etc.

5. Also called tracer ammunition. ammunition containing a chemical substance that causes a projectile to trail smoke or fire so as to make its path visible and indicate a target to other firers, especially at night.

6. the chemical substance contained in such ammunition.

7. a substance, especially a radioactive one, traced trace through a biological, chemical, or physical system in order to study the system.

tracer

/ ˈtreɪsə /

noun

1. a person or thing that traces

2. 1. a projectile that can be observed when in flight by the burning of chemical substances in its base

   2. ammunition consisting of such projectiles

   3. ( as modifier )

      tracer fire

3. med any radioactive isotope introduced into the body to study metabolic processes, absorption, etc, by following its progress through the body with a gamma camera or other detector

4. an investigation to trace missing cargo, mail, etc

tracer

1. An identifiable substance, such as a dye or radioactive isotope, that can be followed through the course of a mechanical, chemical, or biological process. Tracers are used in radioimmunoassays and other laboratory testing. The use of radioactive iodine, for example, can give information about thyroid gland metabolism.

2. Also called label

Word History and Origins

Origin of tracer¹

First recorded in 1535–45; trace ¹ + -er ¹

Example Sentences

Overnight, AFP journalists saw Ukraine using tracer bullets and missile defence systems, and incandescent debris falling over large areas above the capital.

Read more on Barron's

Oxygen isotopes function as tracers, allowing scientists to learn about water sources, plant transpiration, and atmospheric moisture.

Read more on Science Daily

"The Neuro is one of the few centres worldwide that can produce the tracer and run the scan."

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"In that work, we found that different meteorites have different potassium isotopic signatures, and that means potassium can be used as a tracer of Earth's building blocks," Nie explains.

Read more on Science Daily

One head described it as a "tracer" letter, asking principals if any of the named pupils have subsequently enrolled in a different school.

Read more on BBC