A famous person or thing is known to more people than a well-known one. A notorious person or thing is famous because they are connected with something bad or undesirable. Infamous is not the opposite of famous. It has a similar meaning to notorious, but is a stronger word. Someone or something that is notable is important or interesting.

famous 比 well-known 表示的知名度更高，notorious 则表示得名于某种坏事或令人厌恶之事。infamous 不是 famous 的反义词，它与 notorious 词义相近，但比 notorious 语气更强。notable 则指重要的或有趣的。