pronunciation of rarefied
Definition of RAREFACTION. 1. : the action or process of rarefying. 2. : the quality or state of being rarefied. 3. : a state or region of minimum pressure in a medium traversed by compressional waves (as sound waves). â rarÂ·eÂ·facÂ·tionÂ·al \-shnÉl, -shÉ-nÉl\ adjective. See rarefaction defined for kids. ADVERTISEMENT.