The antonyms for "after-glow," which refer to a lingering brightness or warmth after something has ended, are many. These include darkness, coldness, and gloom. Other antonyms for "after-glow" could be emptiness, lack of satisfaction, or disappointment. These antonyms suggest that instead of a fulfilling conclusion, there was an absence of fulfillment or a feeling of letdown. Another antonym for "after-glow" could be a quick fade, signifying that there was no lasting impact of the event or experience, or that it was easily forgotten. Overall, the antonyms for "after-glow" are a stark contrast to the warm and comforting feeling associated with its definition.