Definition of "rarefy" []

• To make thin, less compact, or less dense. (verb-transitive)
• To purify or refine. (verb-transitive)
• To become thin or less compact or dense. (verb-intransitive)

American Heritage(R) Dictionary of the English Language, Fifth Edition. Copyright (c) 2011 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.

• "I'm no stranger to the Gentri-verse and I ride my bike all the time, and I can't even relate to him--which, I guess, is why I also can't always relate to the "bike culture," since they seem so determined to rarefy the normal."
• "Because the elements, on the other hand, can be rarefied and condensed, they can incline the lumen in themselves away from the center of the universe, so as to rarefy it, or toward the center so as to condense it, and this accounts for their natural capacity to move up and down."
• "Special clamps can be made to hold the cottle in position and are very convenient if many moulds are to be made, but this is rarefy done."