Percussion

1. n. The act of tapping or striking the surface of the body in order to learn the condition of the parts beneath by the sound emitted or the sensation imparted to the fingers. Percussion is said to be immediate if the blow is directly upon the body; if some interventing substance, as a pleximeter, is, used, it is called mediate.
2. n. The act of percussing, or striking one body against another; forcible collision, esp. such as gives a sound or report.
3. n. Hence: The effect of violent collision; vibratory shock; impression of sound on the ear.

The word meanings were obtained from OPTED(The Online Plain Text English Dictionary), which is based on “The Project Gutenberg Etext of Webster’s Unabridged Dictionary” which is in turn based on the 1913 US Webster’s Unabridged Dictionary (See Project Gutenburg), as a text file.