Definition of tracer
1 : one that traces, tracks down, or searches out: such asa : a person who traces missing persons or property and especially goods lost in transitb : 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
4a : ammunition containing a chemical composition to mark the flight of projectiles by a trail of smoke or lightb : a substance used to trace the course of a chemical or biological process; especially : label 3d
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 of tracer from the Web
With two outs and the bases loaded in the seventh, Chris Taylor crushed a fastball from Craig Stammen, sending a tracer over the left-field wall.
Cameras were set up at Wallops and in Duck, N.C., to track the color tracers through the air.
The vapor tracers will allow scientists on the ground to view the movement of the particles in the ionosphere, a part of Earth's atmosphere that stretches to the edge of space, to learn more about the movement of the air currents at that altitude.
Muzzle flashes lit up the jungle, tracer bullets from anti-aircraft guns scouring the humid air.
Three chemicals will interact to form the color tracers — barium, strontium and cupric-oxide.
But for the tracer experiments, the metals are released in much lesser amounts.
The vapor tracers may be visible from New York to North Carolina and westward to Charlottesville, Virginia.
This map shows the projected visibility of the vapor tracers during the June 2 mission.
These example sentences are selected automatically from various online news sources to reflect current usage of the word 'tracer.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.
First Known Use of tracer
TRACER Defined for English Language Learners
Definition of tracer for English Language Learners
: a type of bullet that shows its path by creating smoke or light as it moves through the air
medical : a substance that is put in a patient's body so that doctors can watch a biological process (such as digestion) or see how a condition (such as cancer) is progressing
Seen and Heard
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