specter

Compared meaning: a ghost, the spirit of a dead person (noun).

比较义项：鬼魂、幽灵（名词）。

• ghost

  The everyday, neutral word for the spirit of a dead person; used in ordinary conversation, folklore, and children's stories without any special tone.

  这是最普通、最中性的说法，指已故之人的灵魂；常用于日常对话、民间传说和儿童故事，没有特殊的语气色彩。

  My grandmother swears she saw a ghost walking down the hallway at midnight.

  我祖母坚称她在午夜看到一个鬼魂走过走廊。

• spook

  An informal, chiefly American word for a ghost, casual in spoken English; it can also be used as a verb meaning to frighten someone.

  这是非正式说法，主要用于美式口语，语气比较随意；它也可以用作动词，表示“吓唬”某人。

  Old sailors used to claim the ship was haunted by spooks.

  老水手们以前常说这艘船被幽灵缠身。

• specter 本词

  A formal, literary word, often used figuratively for an ominous, threatening presence or possibility looming over people rather than a literal ghost.

  这是较为正式、文学化的词，常用于比喻意义，指笼罩着人们、令人恐惧的威胁或不祥预兆，而不是字面意义上的鬼魂。

  The specter of layoffs loomed over the factory for months.

  裁员的幽灵笼罩着这家工厂长达数月。

All three mean the spirit of a dead person, but register differs. Ghost is the common, neutral word. Spook is informal, and can be a verb meaning 'to frighten'. Specter is formal and literary, often describing a frightening presence. Spook's 'spy' sense is not compared.

这三个词都表示已故之人的灵魂或鬼魂，但正式程度和语气不同：ghost最常见、最中性；spook是非正式说法，尤见于美式口语，也可作动词表示“吓唬”；specter较为正式、文学化，常用于比喻令人恐惧、挥之不去的威胁或凶兆。这里不比较spook作“间谍”的俚语义，也不比较ghost作动词表示“突然断绝联系”的现代用法。