In English vocabulary, the verb "partition" means to divide or split something into separate parts. Which of the following words is most nearly its opposite in meaning?

Introduction / Context:
This question tests your knowledge of antonyms, that is, words with opposite meanings. The target word is "partition", which appears in everyday contexts such as partitioning a room or partitioning a hard drive. Understanding its meaning and opposite helps you in vocabulary sections of competitive exams and in reading technical as well as general texts.

Given Data / Assumptions:
- The given meaning of "partition" is to divide or split something into parts.
- We must choose a word that expresses the opposite action.
- Options include "mark off", "divide", "attach", "separate", and "split".

Concept / Approach:
If "partition" means to break or divide something into pieces or sections, then its opposite will mean to join pieces together or to bring separate parts into a whole. Among the options, "attach" clearly suggests joining or connecting one thing to another. The other options are either synonyms or near synonyms of "partition". Therefore, "attach" is the correct antonym.

Step-by-Step Solution:
Step 1: Restate the meaning of "partition": to divide, separate, or split something.
Step 2: Look for a word that expresses joining rather than dividing.
Step 3: Notice that "attach" means to join, connect, or fix one thing to another.
Step 4: Confirm that other options like "divide", "separate", and "split" are similar in meaning to "partition" and therefore cannot be the opposite.

Verification / Alternative check:
Imagine an example: you have a large hall. If you partition the hall, you build walls or screens so that it becomes several smaller rooms. The opposite action would be to remove partitions and attach or join sections so that it again becomes one large space. In technical language, if you partition a hard drive, you divide it into parts; the opposite would be to merge or attach those parts. This mental picture clearly supports "attach" as the antonym.

Why Other Options Are Wrong:
- mark off: means to set boundaries or separate an area, which is similar to partition, not opposite.
- divide: directly expresses splitting into parts, almost the same as partition.

- separate: again, to put things apart, which is a synonym, not an antonym.
- split: another word for breaking into pieces, similar in meaning.

Common Pitfalls:
Sometimes candidates quickly select a familiar word like "divide" or "separate" without carefully reading that the question asks for the opposite meaning. Remember to check whether the question is asking for a synonym or an antonym. A good strategy is to mentally write a sentence with the original word and then reverse the action in your mind to see what opposite verb fits logically.

Final Answer:
The opposite of "partition" in this context is "attach".