Choose the one word that can be substituted for the given phrase: "Any morbid dread of water."

Introduction / Context:
This one word substitution question focuses on a medical or psychological term described in simple language as "Any morbid dread of water." The phrase refers to an extreme, abnormal fear, not just a casual dislike. Many English words describing fears use the suffix "phobia", which comes from Greek. Recognising this pattern makes it much easier to select the correct term from the options.

Given Data / Assumptions:
• Phrase: "Any morbid dread of water." • Options: Hydrofoil, Hydrophobia, Hydraulic, Hyacinth. • The key ideas are "morbid dread" (abnormal fear) and "water". • "Hydro" is a root that relates to water.

Concept / Approach:
The word "Hydrophobia" is formed from "hydro", meaning water, and "phobia", meaning fear. Together, they literally describe a fear of water. It is sometimes used as a symptom name in diseases such as rabies, where patients develop a strong fear of water. The other options do not describe a fear at all. Hydrofoil refers to a type of boat or wing like structure, hydraulic is related to systems driven by fluid under pressure, and hyacinth is a flower. Thus, the only term that fits the idea of a morbid dread of water is hydrophobia.

Step-by-Step Solution:
1. Break the phrase into key parts: "morbid dread" indicates an abnormal fear, and "water" indicates the object of that fear. 2. Recall that "phobia" is a suffix used in words like arachnophobia or claustrophobia to mean fear. 3. Notice that "hydro" is a root for water, used in words such as hydration or hydroelectric. 4. Combine these roots conceptually to form "hydrophobia", which means fear of water. 5. Compare this with "hydraulic", which refers to machines or systems operated by water or oil under pressure. 6. Compare with "hydrofoil", which is related to a type of boat, and "hyacinth", which is the name of a plant, not a fear.

Verification / Alternative check:
You can verify by recalling that in some medical contexts, hydrophobia is associated with the later stages of certain infections where the patient cannot drink water and becomes fearful of it. The structure of the word clearly suggests water fear. None of the other options contain the "phobia" element or describe a psychological state. This cross checking with both word structure and basic general knowledge confirms that hydrophobia is the correct answer.

Why Other Options Are Wrong:
Option A, hydrofoil, refers to a kind of boat or wing structure used to lift a vessel above water to reduce drag. Option C, hydraulic, is an adjective used for machinery and systems powered by fluids under pressure, not a fear. Option D, hyacinth, is the name of a flowering plant and has no connection to fear or water in the sense required here. These words either belong to engineering or botany and therefore do not match the phrase "morbid dread of water".

Common Pitfalls:
Learners may get distracted by the common root "hydro" and choose any option containing it, such as hydrofoil or hydraulic, without noticing that the phrase is describing a fear. The important clue is the word "dread", which should immediately suggest something ending in "phobia". To avoid similar mistakes, train yourself to look for these clear signals in the definition when dealing with one word substitution questions involving medical or psychological terms.

Final Answer:
The correct one word substitute for "Any morbid dread of water" is Hydrophobia.