1. ethereal characterized by lightness and insubstantiality
  2. Athyrium temperate and tropical lady ferns
  3. atrium a chamber connected to other chambers or passageways
  4. atheroma a fatty deposit in the intima of an artery
  5. yttrium a silvery metallic element that is common in rare-earth minerals; used in magnesium and aluminum alloys
  6. atheneum a literary or scientific association for the promotion of learning
  7. weather atmospheric conditions such as temperature and precipitation
  8. Euderma a genus of Vespertilionidae
  9. athenaeum a literary or scientific association for the promotion of learning
  10. adhere stick to firmly
  11. theorem an idea accepted as a demonstrable truth
  12. ether compound with an oxygen atom linking two hydrocarbon groups
  13. water yam grown in Australasia and Polynesia for its large root with fine edible white flesh
  14. interim the time between one event, process, or period and another
  15. thorium a soft silvery-white tetravalent radioactive metallic element; isotope 232 is used as a power source in nuclear reactors; occurs in thorite and in monazite sands
  16. etherize anesthetize with ether
  17. ytterbium a soft silvery metallic element
  18. etherise anesthetize with ether
  19. anthurium any of various tropical American plants cultivated for their showy foliage and flowers
  20. therm a unit of heat equal to 100,000 British thermal units