Step 1: Understanding the Concept:
Advanced English vocabulary tests often include "look-alike" words—words that sound nearly identical but have completely distinct definitions.
The word "TURPID" is frequently confused with three other words: Turgid, Turbid, and Torpid.
The key to solving this question is knowing the specific noun associated with "turpid," which is "turpitude."
Step 2: Detailed Explanation:
Let us clarify the definitions of the word "TURPID" and distinguish it from its close linguistic relatives:
1. TURPID (Target): This adjective means base, foul, or morally depraved.
It is most commonly associated with the phrase "moral turpitude," used in legal contexts to describe wicked or shameful behavior.
2. Foul or depraved (Option A): This is the correct definition. It refers to a state of moral corruption or physical filthiness.
3. Swollen and distended (Option B): This is the definition for Turgid (or tumid).
Example: "The river was turgid after the heavy rains." This is a classic "look-alike" trap.
4. Muddy and cloudy (Option C): This is the definition for Turbid.
It describes thick, cloudy liquids where the sediment has been stirred up.
Example: "The turbid waters of the lake made it impossible to see the bottom."
5. Lethargic (Option D): This is the definition for Torpid.
It means mentally or physically inactive or sluggish.
Example: "A bear is in a torpid state during winter hibernation."
By carefully separating these four terms, we can confidently identify that "turpid" refers to the "foul/depraved" category.
Step 3: Final Answer:
TURPID means foul or depraved.
Therefore, the correct option is (a).