nacreous clouds

英 美
  • 珠母云
  • clouds n.云;烟云名词cloud的复数形式.
  • nacreous adj.含有珍珠母的;有珍珠光泽的;象珍珠质的
名词 nacreous cloud:
  1. a luminous iridescent cloud at a high altitude that may be seen when the sun is a few degrees below the horizon