Definition of Lucid

Adjective: lucid loo-sid

(of language) transparently clear; easily understandable
"lucid directions";
- limpid, luculent, pellucid, crystal clear, perspicuous
Having a clear mind
"a lucid moment in his madness"
Capable of thinking and expressing yourself in a clear and consistent manner
"a lucid thinker";
- coherent, logical
Transmitting light; able to be seen through with clarity
"lucid air";
- crystalline, crystal clear, limpid, pellucid, transparent