In a legal context, lucid refers to a state of being clear and able to think and understand in a rational manner. It can also refer to a person’s ability to communicate in a clear and coherent way. It is often used to refer to a person’s mental state and their ability to understand legal proceedings and make decisions.

For example, if a person is found to be lucid, they may be considered competent to stand trial, make a will, or testify in court. If a person is determined to be not lucid, they may be declared legally incompetent, and a guardian or conservator may be appointed to make decisions on their behalf.

In general, “lucid” is an adjective that means clear, easily understood and rational, it can be used in different fields as well.