A polite stand-in for the devil. You want the force of the strong word without saying it, so you drop a harmless-looking name into its place — and the force stays, while the offence goes.
Recorded around 1590-1600, apparently a playful use of the personal name Dicken, a pet form of Dick, standing in for 'devil'.
大約 1590 到 1600 年間出現，看起來是把人名 Dicken（Dick 的小名）開玩笑地拿來頂替 devil。要注意：它比小說家 Charles Dickens 早了兩百多年，兩者沒有關係。
Wiktionary entry 'dickens' (kaikki extract, source_ref kaikki:3f6f69a190036ae4:930248573), etymology_text: 'Origin: 1590-1600; apparently a fanciful use of the proper name Dicken, diminutive form of Dick.'
Two branches
魔鬼的替身
這是這個字本身的意思，其他用法都從它借力。
noun · C2
A mild, old-fashioned word for the devil, used so that you do not have to say a stronger word. You meet it inside set expressions such as 'scare the dickens out of someone' (frighten someone badly) and 'the dickens of a ...' (a very difficult or very bad one).
魔鬼（委婉說法）
借來加強語氣
替身站進句子以後就不指東西了，只負責加力道——這兩個用法都是這樣。
noun · C2
Put straight after what, who, where, why or how in a question, to show that you are very surprised or annoyed. 'What the dickens is going on?' does the same job as 'What on earth is going on?'
究竟、到底（表驚訝或惱火）