Bullets which include a pyrotechnic component, allowing their path through the air to be seen.

Bullets or other projectiles which include a pyrotechnic component, allowing their path through the air to be seen.

plural of tracer bullet

plural of contact tracer

(epidemiology) A person engaged in contact tracing.

plural of path tracer

A program or algorithm for path tracing.

(architecture) Bars or ribs, usually of stone or wood, or other material, that subdivide an opening or stand in relief against a door or wall as an ornamental feature.

plural of tracery

Decorated with tracery