Final answer:
The word 'lucid' means clear or comprehensible, which makes 'comprehensible' the correct answer as it also implies something that is easy to understand.
Step-by-step explanation:
The word lucid most closely means comprehensible. 'Lucid' is typically used to describe clear thinking or expression. Among the options given, 'comprehensible' is similar in meaning because it refers to something that is easy to understand or grasp. The other options, such as 'deceitful', 'secure', and 'murky', are not similar in meaning to 'lucid'. 'Deceitful' refers to dishonesty, 'secure' relates to safety or stability, and 'murky' signifies something that is unclear or difficult to see through, which is the opposite of lucid.