Select the antonym of the noun “eternity”.

Introduction / Context:
This question tests your understanding of antonyms in English vocabulary. The word eternity refers to endless time or a state that lasts forever. Examinations often pair such abstract nouns with adjectives or nouns that express the opposite idea, such as shortness or brevity. You must identify the option that conveys the opposite meaning of eternity.

Given Data / Assumptions:

• Word given: eternity.
• Options: perpetuity, yonder, aeon, ephemeral.
• One option must express the idea of being short lived or temporary, which is opposite to the idea of endless time.

Concept / Approach:
Eternity refers to infinite or unending time. Words like perpetuity and aeon are close in meaning to very long duration or endless time, so they are near synonyms. Yonder refers to distance, not time. Ephemeral, on the other hand, is an adjective that means very short lived, lasting for a brief time only. So the correct antonym of eternity is ephemeral.

Step-by-Step Solution:
Step 1: Recall the meaning of eternity: endless time or existence without end. Step 2: Examine perpetuity. This noun means the state of lasting forever or for an indefinitely long period, which is similar in meaning to eternity, so it is not an antonym. Step 3: Examine yonder. This word indicates something at some distance in space, usually meaning over there. It does not relate to duration and therefore cannot be considered an opposite of eternity. Step 4: Examine aeon. An aeon is an extremely long period of time, also close in sense to eternity in many contexts. Step 5: Examine ephemeral. This adjective means short lived or lasting for a very brief time, like ephemeral beauty or ephemeral trends. Step 6: Since ephemeral expresses the idea of brief duration, it is the opposite of endless duration and so is the antonym of eternity.
Verification / Alternative check:
Think of example phrases: eternal love, eternal life, and eternity all suggest something that does not end. Ephemeral flowers, ephemeral fame, or ephemeral moments are those that pass quickly. When we look for opposites, we match endless with very short lived. On the other hand, perpetuity shares the root idea of continuing forever (as in bonds in perpetuity), and aeon describes immense spans of time. This contrast confirms ephemeral as the correct answer.

Why Other Options Are Wrong:

• perpetuity: Means lasting forever or for an indefinitely long time, so it is a synonym rather than an antonym.
• yonder: Refers to distance, not time, so it does not meaningfully contrast with eternity.
• aeon: Means a very long period of time, conceptually close to eternity rather than opposite.

Common Pitfalls:
Candidates sometimes rush to pick a rare looking word like aeon, assuming that rarity means correctness. Others mix up synonyms and antonyms if they do not read the question carefully. Always focus on the instruction select the antonym and compare each option with the original word. Also remember common collocations such as ephemeral joy and ephemeral glory, which emphasise short duration, making them good antonyms for eternal or everlasting.

Final Answer:
The antonym of eternity is ephemeral.