Englishئاساسىي لۇغەت
tracer
Universal Words
noun
1 a bullet or SHELL (= a kind of bomb) that leaves a line of smoke or flame behind it:
tracer bullets
2 (technical) a RADIOACTIVE substance that can be seen in the human body and is used to find out what is happening inside the body:
Radioactive tracers have been used to map the metabolic activity of the brain.
