One who, or that which, traces.
- One who is employed to locate missing goods or persons.
- An investigation or inquiry organized to trace missing goods or persons.
- Any of several instruments used in making tracings or in imprinting designs by tracing.
- A tracer bullet.
- An identifiable substance, such as a dye or a radioactive isotope, that is introduced into a biological or mechanical system and can be followed through the course of a process, providing information on the pattern of events in the process or on the redistribution of the parts or elements involved. Also called label.