rarefy是什么意思？

rarefy

英['reərɪfaɪ] 美[ˈrɛrəˌfaɪ]

• vt. 使稀薄，（思想等）精炼，使纯化，使变得精妙深奥；

第三人称单数：rarefies;

过去式：rarefied;

过去分词：rarefied;

现在分词：rarefying;

英英词典释义

• Verb
  1. lessen the density or solidity of;
  "The bones are rarefied"
  2. make more subtle or refined
  3. weaken the consistency of (a chemical substance)