Tracer Meaning
/ˈtɹeɪsə(ɹ)/Definition, CEFR level B2, pronunciation, examples, and quiz.
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Definition
nounA compound, element, or isotope used to track the progress or history of a natural process.
nounA round of ammunition for a firearm that contains magnesium or another flammable substance arranged such that it will burn and produce a visible trail when fired in the dark.
Sentence Examples
Positron Emission Tomography uses a radioactive tracer to visualize metabolic activity within the human body.
The doctor injected a radioactive tracer to follow blood flow.
CEFR Practice Quiz
The sniper used a ____ round to see where the shot landed at night.
CEFR Practice Quiz (Alternate)
The doctor used a radioactive ____ to track the flow of blood through the patient's heart during the scan today.
Word Origin & History
Etymology tree English trace English -er English tracer From trace + -er.
Literary Quotations & Historical Citations
"We have a five-man tracer on him now. He's heading for a Vorster cell on Michigan Boulevard, and he's drunk as a lord. Should we intercept him?"
— 1964, Galaxy Magazine, volume 23, numbers 1-6, page 125:
"A surveyor typically conducts a tracer on his or her own and later meets up with the rest of the team to discuss findings."
— 2011, Joint Commission Resources, Environment of Care Tracer Workbook, →ISBN, page 5:
"Ain't never running but I'm a paper chasing
They gon catch up to me, they gon need a pacer
How they over-watching me without a tracer"
— 2017, “From the Sewers”, CardCaptorXP (lyrics):
"The next morning when she awoke, she told Darcy what had happened, and Darcy agreed that she should go to the police and this time ask them if they could put a tracer on her incoming phone calls, just in case he called again."
— 2010, Claire Gilbert, A Runway for a Dream:
Explore More B2 Vocabulary Words
CEFR Practice Quiz
The sniper used a ____ round to see where the shot landed at night.
CEFR Practice Quiz (Alternate)
The doctor used a radioactive ____ to track the flow of blood through the patient's heart during the scan today.