unseen

Compared meaning: not able to be seen (adjective).

比较义项：看不见的、未被察觉的（形容词）。

• invisible

  Means something cannot be seen at all, usually because of its physical nature — too small, transparent, or absent — rather than being deliberately concealed.

  表示某物根本看不见，通常是因为其物理属性——太小、透明或根本不存在——而不是被故意藏起来。

  Bacteria are invisible without a microscope, no matter how hard you look.

  如果没有显微镜，细菌是看不见的，无论你多么努力地看。

• hidden

  Implies something is intentionally placed out of sight in a specific location, and could still be discovered if someone searched for it.

  表示某物被有意放在某个隐蔽的地方，如果有人去寻找，仍然可以被发现。

  She found a hidden compartment behind the wardrobe when she moved the furniture.

  她把家具挪开后，发现了衣柜后面一个隐藏的隔层。

• unseen 本词

  Simply means nobody has noticed or witnessed something; it does not imply the thing is impossible to see or that it was deliberately concealed.

  只是表示没有人注意到或目睹某件事，并不意味着这件事不可能被看见，也不意味着它被故意藏起来。

  The accident happened unseen, since everyone had already left the room.

  那场事故发生时无人看见，因为大家都已经离开了房间。

Invisible, hidden, and unseen all mean not able to be seen, but the reason differs. Invisible means something cannot be seen, due to its physical nature. Hidden means something is deliberately placed out of sight, but could still be found. Unseen means nobody noticed it.

这三个词都表示某物看不见，但原因不同：invisible 强调因物理原因根本无法被看见；hidden 强调被有意或物理地藏在某处，仍然可以被找到；unseen 只是强调没有人碰巧看到或注意到，并不涉及是否可能看见，也不涉及是否被藏起来。