tracer

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.

In ordnance, an attachment, to a projectile for use at night, provided with a burning composition by means of which, when the projectile is fired from a gun, its path throngh the air is rendered visible.

One who or that which traces, in any sense.

A small slender steel instrument, having a handle in the middle and its ends pointed more or less, and one of them usually also curved and edged, used in dissection as a compromise between scalpel and probe for tracing out the course of nerves, vessels, etc. It is usually held like a pen, and may be pushed into or drawn through tissue, as desired. Also called seeker.

One whose duty it is to trace or search out missing articles, as railway-cars, milk-cans, or letters.