Finding the Right One-Word Substitute

The question asks for a single word that means to "Fall back or sink again (into a worse state after an improvement)". This phrase describes a situation where someone or something improves, but then goes back to a previous, worse condition.

Let's look at the given options and their meanings:

• Rekindle: To revive or restart something, especially a feeling or relationship. This means to bring something back to life, often in a positive sense.
• Reiterate: To say something again or a number of times, typically for emphasis or clarity. This is about repeating words or statements.
• Relayed: To receive and pass on information or a message. This is about transmitting information.
• Relapse: A deterioration in someone's state of health after a temporary improvement. It can also be used more broadly to mean falling back into an old habit or a worse state after improvement.

Comparing the meaning of the phrase "Fall back or sink again (into a worse state after an improvement)" with the meanings of the options, we can see that 'Relapse' perfectly matches the description.

Here's why the other options do not fit:

• 'Rekindle' implies bringing something back, usually in a positive or neutral way, not necessarily sinking into a worse state.
• 'Reiterate' is about repeating something, related to communication, not falling back into a worse state.
• 'Relayed' is also about communication, transmitting information, not a decline in condition.

Therefore, 'Relapse' is the correct one-word substitute for the given group of words.

Detailed Analysis of the Correct Term: Relapse

The word 'Relapse' is commonly used in medical contexts to describe a patient whose health deteriorates after showing signs of recovery. However, its meaning extends beyond health to any situation where there is a return to a previous, undesirable state after a period of improvement. For example, someone who has quit smoking might relapse and start smoking again. This matches the core idea of falling back or sinking again into a worse state.

Comparison of Options

Revision Table: Vocabulary Terms

Additional Information: Understanding Vocabulary in Context

When solving one-word substitution questions, it's important to understand the precise meaning of the phrase given and the nuances of the words provided in the options. Often, several words might seem similar, but only one will perfectly capture the intended meaning. Paying attention to keywords in the phrase, such as "worse state" and "after an improvement" in this case, helps eliminate incorrect options and identify the correct one, which is 'Relapse'. Building a strong vocabulary by learning word definitions and seeing how words are used in different contexts is crucial for mastering such questions.