1. A reproduction made by superimposing a transparent sheet and copying the lines of the original on it.
2. A graphic record made by a recording instrument, such as a cardiograph or seismograph.

The American Heritage® Dictionary of the English Language, Fourth Edition Copyright © 2007, 2000 by Houghton Mifflin Company. Updated in 2009. Published by Houghton Mifflin Company. All rights reserved.