- tracer
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/tray"seuhr/, n.1. a person or thing that traces.2. a person whose business or work is the tracing 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 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, esp. at night.6. the chemical substance contained in such ammunition.7. a substance, esp. a radioactive one, traced through a biological, chemical, or physical system in order to study the system.[1535-45; TRACE1 + -ER1]
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detectable substance added to a chemical, biological, or physical system to follow its process or to study distribution of the substance in the system. Tracer dyes have long been used to follow the flow of underground streams. Incendiary rounds included at intervals in a belt of machine-gun bullets make the paths of the bullets visible. In scientific work, the use of tracers has increased and, because of the sensitivity of modern methods, has helped solve many problems. Particularly effective modern methods utilize isotopic tracers. See isotopic tracer.* * *
Universalium. 2010.
