IPA: /ˈtreɪsər/
KK: /ˈtreɪsər/
A person or thing that traces or follows something, often used to refer to a bullet that leaves a visible trail or a substance that can be tracked in a system.
The detective hired a tracer to find the missing person.
Tracer → It is formed from "trace" (from Old French *tracier*, meaning to draw or mark) and "-er" (meaning a person who). A tracer is a person who draws or marks something, often used in contexts like tracing a path or outline.
Think of someone who 'draws' or 'marks' ('trace') something, and the '-er' indicates that this person is doing the action. This helps you remember that a tracer is someone who traces.