clear, translucent
clearly expressed; easy to understand 表达清楚的；易懂的 SYN clear
a lucid style/explanation
明白易懂的风格；清楚的解释
able to think clearly, especially during or after a period of illness or confusion （尤指生病期间或病愈后，糊涂状态中或过后）头脑清晰的，清醒的
In a rare lucid moment, she looked at me and smiled.
在难得清醒的时刻，她看看我，笑了笑。