rarefy

vt. 使稀少,使稀薄,使纯化 vi. 变稀少,变稀薄

rapidity, rapidly, rapids, rapier, rapier-thrust, rapine, rapist, rapport, rapprochement, rapscallion, rapt, raptly, rapture, rapturous, rapturously, rare, rare earth, rarebit, rarefaction, rarefied, rarely, rareness, raring, rarity, rascal, rascally, rase, rash, rasher, rashly, rashness, rasp, raspberry, raspy, Rastafarian, rat, rat-a-tat-tat, rat-tat, ratatat, ratbag,