Understanding the Question: One-Word Substitution for Decisions

The question asks for a single word that can replace the phrase "A decision which cannot be taken back". This means we are looking for a word that describes something that is final, irreversible, and cannot be undone or changed after it has been made.

Analyzing the Options for the Decision

Let's examine each of the provided options to see which one best fits the description of a decision that cannot be reversed.

1. irrevocable: This word means unable to be changed, reversed, or recovered. If a decision is irrevocable, it means it is final and cannot be taken back.
2. infallible: This word means incapable of making mistakes or being wrong. While being right might be good, it doesn't mean the decision itself cannot be reversed later, even if it was the correct one at the time. This word relates to accuracy, not permanence of the decision.
3. irrational: This word describes something that is not based on reason or logic. An irrational decision might be a bad one, but being irrational does not automatically mean it cannot be reversed or changed later.
4. indelible: This word means making marks that cannot be removed, or producing a lasting impression. It is often used for things like ink, memories, or impressions. While it implies permanence, it is not the standard term used to describe a decision that cannot be reversed. 'Irrevocable' is the more precise term for decisions.

Identifying the Most Appropriate One-Word Substitution

Based on the definitions, the word that most accurately describes "A decision which cannot be taken back" is irrevocable.

• Irrevocable decisions are final.
• Infallible relates to being correct, not irreversible.
• Irrational relates to lack of logic, not irreversibility.
• Indelible relates to permanence, but is less specifically used for decisions than 'irrevocable'.

Detailed Explanation of the Correct Term

The word irrevocable is formed from the prefix 'ir-' (meaning not), 'revoke' (meaning to cancel or withdraw), and the suffix '-able' (meaning capable of). So, irrevocable literally means not capable of being revoked or cancelled. This perfectly matches the definition of a decision that cannot be taken back.

Therefore, irrevocable is the most appropriate one-word substitution for "A decision which cannot be taken back".

Revision Table: Key Vocabulary

Additional Information on Irrevocable Decisions

In various fields, the concept of an irrevocable decision or action is important:

• Law: An irrevocable trust is one that cannot be altered or terminated by the grantor. An irrevocable offer in contract law cannot be withdrawn by the offeror during a specified period.
• Finance: An irrevocable letter of credit is a guarantee from a bank that a payment will be made, and it cannot be cancelled by the bank or the buyer without the seller's consent.
• Everyday Life: While most personal decisions can be changed, some actions, like selling a property or signing a binding contract, can lead to consequences that are effectively irrevocable.

Understanding the meaning of irrevocable is crucial for comprehending situations where actions have permanent consequences.