In this verbal aptitude odd-man-out question on clothing vocabulary, four garment names are given: Trousers, Shirt, Pants and Shorts. Three of these items are primarily worn on the lower part of the body, whereas one is normally worn on the upper part. Which word is the odd one out based on how the garment is usually worn?

Introduction / Context:
This problem is a verbal reasoning odd-man-out question focusing on everyday clothing vocabulary. Such questions test your ability to group items based on a logical property, such as usage, category or function. Here, all the options are names of garments, but one of them differs in the part of the body on which it is usually worn. Understanding this context helps you quickly see the relationship among the words and identify the item that does not belong to the main group.

Given Data / Assumptions:
The options are Trousers, Shirt, Pants and Shorts.
All four are common items of clothing.
You are expected to find which garment does not fit with the others based on typical usage.
Assume normal, everyday meaning of the words in modern English clothing terminology.

Concept / Approach:
The key idea in this question is categorization of garments based on the part of the body they cover. Trousers, Pants and Shorts are generally worn on the lower part of the body and cover the legs to different extents. A Shirt, on the other hand, is a garment worn on the upper part of the body, covering the torso and often the arms. By grouping items according to whether they are lower-body or upper-body garments, we can identify the odd word. This kind of reasoning is common in aptitude exams where conceptual grouping is more important than any complicated linguistic rule.

Step-by-Step Solution:
Step 1: Examine Trousers. They are lower-body garments that cover the legs from waist to ankles. Step 2: Examine Pants. In many contexts, especially American English, Pants also refer to lower-body garments similar to trousers. Step 3: Examine Shorts. Shorts are lower-body garments that cover only part of the legs, usually from the waist to somewhere above the knees. Step 4: Examine Shirt. A Shirt is worn on the upper body, covering the chest, back and often the arms, and is not a lower-body garment. Step 5: Conclude that three options are lower-body garments, while Shirt is an upper-body garment and is therefore the odd one out.
Verification / Alternative check:
Another simple way to verify is to imagine getting dressed. When you think of what you wear below the waist, you might choose trousers, pants or shorts. In contrast, when you think of what you wear above the waist, you think of a shirt. This intuitive check confirms the categorization: three items go into the lower-body group and one item clearly belongs to the upper-body group. That one must be the odd option.

Why Other Options Are Wrong:
Trousers are lower-body garments and belong in the same category as pants and shorts, so they are not odd.
Pants are also lower-body garments and fit the main pattern, so they cannot be the odd one.
Shorts again are worn on the lower body, so they are similar to trousers and pants and are not the odd word.
Shirt is the only upper-body garment, making it the unique and correct odd-man-out choice.

Common Pitfalls:
A common mistake is to focus on the plural or singular form of the words, for example noticing that Shirt is singular while some of the others are often used in plural. However, grammatical number is not the intended logic here. The relevant property is functional use on the body. Another possible distraction is thinking about formal versus casual clothing, but both trousers and shorts can exist in casual or semi-formal forms. Always ask what fundamental property can cleanly group three items together and separate one as different.

Final Answer:
The odd clothing item, because it is worn on the upper part of the body while the others are lower-body garments, is Shirt.