a.

1. 清楚易懂的，明晰的
   lucid instructions

   清楚易懂的指示

2. 头脑清楚的；神志清明的
   lucid intervals

   神志清醒期间

3. 透明的；清澈的
   a lucid stream

   清澈的小溪

4. 【诗】明亮的

adj.

1. clear; easy to understand.
   ▸showing an ability to think clearly.
   ▸Psychology  (of a dream) in which the sleeper is aware of dreaming.
2. literary bright or luminous.