名詞 demon:

1. one of the evil spirits of traditional Jewish and Christian belief
   同義詞：devil, fiend, daemon, daimon
2. a cruel wicked and inhuman person
   同義詞：monster, fiend, devil, ogre
3. someone extremely diligent or skillful

1. He's very violent: it's the demon drink, you know.
   他大撒酒瘋，你要知道就是因?yàn)楹攘四欠N酒。
2. Her husband is a demon for work.
   她丈夫工作起來精力過人。
3. That child is a little demon.
   那個(gè)孩子是個(gè)小搗蛋鬼。

de.mon

n.（名詞）
An evil supernatural being; a devil.
惡魔：罪惡的超自然的人物；魔鬼
A persistently tormenting person, force, or passion:
邪惡的事物，邪念：不斷驅(qū)使人的人、力量或情感：
例句：
the demon of drug addiction.
吸毒成癮

One who is extremely zealous, skillful, or diligent:
精力（或技巧）勝人一籌的人：特別熱情、熟練或勤奮的人：
例句：
worked away like a demon; a real demon at math.
象玩命一樣不斷努力地工作；數(shù)學(xué)天才

Also dae.mon or dai.mon [do.môn.] Greek Mythology An inferior deity, such as a deified hero.
也作 dae.mon 或 dai.mon [do.môn.] 【希臘神話】 半神：地位稍低的神，例如奉若神靈的英雄
Also dae.mon or dai.mon [do.môn.] An attendant spirit; a genius.
也作 dae.mon 或 dai.mon [do.môn.] 守護(hù)神；伴隨的神

來源：
Middle English
中古英語
from Late Latin daemôn
源自 后期拉丁語 daemôn
from Latin [spirit]
源自 拉丁語 [神靈]
from Greek daimôn [divine power] * see d3-
源自 希臘語 daimôn [神的力量] *參見 d3-