rarefied
adjective
[ ˈrɛːrɪfʌɪd ]
• (of air, especially that at high altitudes) of lower pressure than usual; thin.
• "every ounce carried counts triple when you're trudging uphill in rarefied air"
• distant from the lives and concerns of ordinary people; esoteric.
• "rarefied scholarly pursuits"
rarefy
verb
• make or become less dense or solid.
• "air rarefies and degrounds the physical body"
Origin:
late Middle English: from Old French rarefier, or medieval Latin rareficare, based on Latin rarus ‘rare’ + facere ‘make’.
