The correct antonym for EPHEMERAL is Permanent.
The word Ephemeral describes something that lasts for a very short time. It is often used to characterize things that are fleeting, transient, or momentary, like a passing trend, a brief moment of joy, or the delicate beauty of a flower that blooms for only a day. The essence of ephemeral lies in its impermanence and its quick disappearance, highlighting the temporary nature of existence or an event. It suggests a brief, almost ungraspable quality.
In direct opposition, Permanent describes something that lasts or is intended to last indefinitely without significant change. It signifies durability, stability, and an enduring quality, implying that something is fixed, lasting, and not subject to decay or alteration over time. A permanent solution, a permanent residence, or a permanent mark all convey a sense of lasting existence. Therefore, while 'Short-lived,' 'Brief,' and 'Fleeting' are synonyms for 'ephemeral,' 'Permanent' is its precise antonym, representing the complete opposite in terms of duration and persistence.