lucid

Expressed clearly; easy to understand; showing the ability to think clearly.

• lucidity/luːˈsɪdɪti/(n)清晰
• lucidly(adv)清晰地

• lucid explanation
• lucid prose
• lucid dream
• lucid interval
• lucid account

1. 1.Her lucid explanation of quantum mechanics made the subject accessible even to non-scientists. (clear)
2. 2.Despite his illness, he had lucid moments when he could recognise family members and speak coherently. (mentally clear)

• clear/klɪər/— easy to understand — simpler
• coherent/koʊˈhɪərənt/— logical and consistent
• intelligible/ɪnˈtɛlɪdʒɪbl/— able to be understood

from Latin "lucidus" (bright, clear) — "lux" (light) — clear as light