If you describe something as ephemeral, you mean that it lasts only for a very short time.
例句
He talked about the country's ephemeral unity being shattered by the defeat...他谈到战败使得该国短暂的统一彻底破灭。These paintings are in some ways a reminder that earthly pleasures are ephemeral.这些画在某种意义上提醒人们世俗的享乐是短暂的。
英汉词典释义
adj.
短暂的,瞬息的
Most newspapers are of ephemeral interest.多数报纸只能引起读者短暂的注意。
英英词典释义
Adjective
1. enduring a very short time;
"the ephemeral joys of childhood""a passing fancy""youth's transient beauty""love is transitory but at is eternal""fugacious blossoms"