tracer

[Eng. trace (1), v.; -er.] 1. One who or that which traces. "A diligent tracer of the prints of nature's footsteps." -Hake will: On Providence, p. 164. 2. An instrument like a stylus for tracing draw ings, ., on a superimposed sheet of paper, . 3. A simple kind of pantograph (q. v.).