rarefaction Meaning, Definition & Usage

  1. noun a decrease in the density of something
    • a sound wave causes periodic rarefactions in its medium

WordNet

Rar`e*fac"tion noun
Etymology
Cf. F. raréfaction. See Rarefy.
Definitions
  1. The act or process of rarefying; the state of being rarefied; -- opposed to condensation; as, the rarefaction of air.

Webster 1913