der Tracer
Translation
tracer, tracer bullet
Examples
Ein radioaktiver Tracer wurde verwendet.
A radioactive tracer was used.
Das Geschoss war ein Tracer.
The projectile was a tracer.
Grammar Patterns
to use ((sth.)) as a tracer Man verwendet Isotope als Tracer.
Similar Words
die Markierungssubstanz (marking substance), das Leuchtspurgeschoss (tracer bullet)
Etymology
From English 'to trace'. Something used to trace or follow a path.
Memory Tips
It's a direct loanword from English, so just remember it's a masculine noun in German: 'der Tracer'.