Choose the antonym (opposite in meaning) of the word "fatigue".

Introduction / Context:
This vocabulary question asks you to identify the antonym of "fatigue". Antonym questions test your understanding of both the given word and its logical opposite. The word "fatigue" is often used in everyday conversation, health topics, and exam texts, so knowing its opposite is practically useful as well.

Given Data / Assumptions:

• Word given: "fatigue".
• Options: restive, slouch, vigour, tire.
• You must choose the word that is opposite in meaning to "fatigue".

Concept / Approach:
"Fatigue" means extreme tiredness, exhaustion, or weariness, whether physical or mental. The antonym should therefore refer to energy, strength, or liveliness. Some options may be related to tiredness or laziness, which are similar to "fatigue" rather than opposite.

Step-by-Step Solution:
Step 1: Recall that "fatigue" refers to a state of being very tired or lacking energy. Step 2: Examine "restive". This word usually means restless or unable to stay still, especially due to impatience or boredom. It is not the opposite of tiredness; it describes behaviour more than energy level. Step 3: Examine "slouch". This normally means to stand, sit, or move in a lazy, drooping way. It describes posture or manner, often associated with laziness, which is closer to tiredness than to energy. Step 4: Examine "vigour". "Vigour" refers to physical strength, energy, or enthusiasm, which is the clear opposite of fatigue. Step 5: Examine "tire". "To tire" is the verb form related to becoming tired, which is similar in meaning to "fatigue". Step 6: Conclude that "vigour" is the correct antonym.

Verification / Alternative check:
Think of a pair of sentences: "After hours of work, he felt fatigue." "After a good rest, he was full of vigour." These two sentences clearly show opposite states: exhausted versus full of energy. Substituting any of the other options does not create such a clear contrast, confirming that "vigour" is the right choice.

Why Other Options Are Wrong:
"Restive" does not indicate high energy in a healthy way; it suggests impatience or inability to remain calm. "Slouch" indicates poor posture or lazy movement, which is closer in tone to fatigue than its opposite. "Tire" is closely associated with becoming fatigued and clearly not an antonym.

Common Pitfalls:
Exam takers sometimes pick a word that merely sounds "active" or negative without carefully considering whether it is truly opposite. For instance, "restive" may seem energetic, but it does not represent the positive energy and strength that contrasts with exhaustion. Building mental maps of opposites, such as fatigue versus vigour, helps you respond quickly in such questions.

Final Answer:
The antonym of "fatigue" is "vigour".