名詞 ephemeral:

1. anything short-lived, as an insect that lives only for a day in its winged form
   同義詞：ephemeron

形容詞 ephemeral:

1. lasting a very short time
   同義詞：passing, short-lived, transient, transitory, fugacious

1. Such novels came forward to enjoy ephemeral popularity only.
   這樣的小說只是曇花一現(xiàn)的東西而已。
2. Perhaps the least prepossessing quality of Fox was that he cares too much about the ephemeral in politics: and Ford displays excessive zeal, to my mind, in teasing out these cares to the last twist and turn.
   也許福克斯最不逗人喜歡的一點(diǎn)就是他把短促的政治生命看得過于重了。而在我看來，福特在誘使福克斯說出他的這些關(guān)心時(shí)顯得過分熱情，手法千奇百怪，使盡了手段。
3. Short-lived or ephemeral, as a life.
   短命的或短暫的，如生命

e.phem.er.al

adj.（形容詞）
Lasting for a markedly brief time:
短暫的：只存在很短一段時(shí)間的：
例句：
.There remain some truths too ephemeral to be captured in the cold pages of a court transcript or . . . opinion.(Irving R. Kaufman)
.在法庭記錄和意見的冰冷紙頁(yè)中還殘留著一些存在時(shí)間太短而不可捕捉的真理.(歐文R.考夫曼)

Living or lasting only for a day, as certain plants or insects do.See Synonyms at transient
短命的：生命只延續(xù)一天的，如某些植物或昆蟲參見 transient
n.（名詞）
A markedly short-lived thing.
生存極短時(shí)間的事物

來源：
From Greek ephômeros
源自 希臘語(yǔ) ephômeros
ep-, epi- [epi-]
ep-, epi- [在…之前]
hômera [day]
hômera [日]

【引伸】
ephem.eral.ity 或
ephem.eralness
n.（名詞）
ephem.erally
adv.（副詞）