One word for 'that is sure to happen'
is :

Question

One word for 'that is sure to happen'
 is :

Accepted Answer

The word "inevitable" is the correct answer for the phrase "that is sure to happen." Here's a detailed explanation:

1. **Inevitable**: This word means something that is certain to occur or unavoidable. When an event or outcome is described as inevitable, it implies that it is bound to happen and cannot be prevented. This aligns perfectly with the phrase "that is sure to happen," as it conveys the certainty and inevitability of the occurrence.

2. **Oblivious**: This word means being unaware or not conscious of something. It does not relate to the certainty of an event happening. Instead, it describes a state of ignorance or lack of awareness, which is unrelated to the concept of inevitability.

3. **Illusion**: An illusion refers to a false perception or a deceptive appearance. It suggests something that is not real or is misleading. This is the opposite of something that is sure to happen, as an illusion is not based on certainty or reality.

4. **Relevant**: This word means closely connected or appropriate to the matter at hand. While relevance indicates a connection or pertinence, it does not imply certainty or inevitability. Therefore, it does not fit the description of something that is sure to happen.

In conclusion, "inevitable" is the only option that accurately captures the essence of something that is certain to occur, making it the correct answer.