significant

Compared meaning: important, deserving attention (adjective).

比较义项：重要的，值得注意的（形容词）。

• significant 本词

  Used for a measurable or noticeable degree of importance, often describing statistics, changes, or events; neutral in tone and common in formal or scientific writing.

  用于可测量或明显的重要程度，常用来描述统计数据、变化或事件；语气中性，常见于正式或科学写作中。

  Doctors noticed a significant drop in his blood pressure after the surgery.

  医生发现他手术后血压有显著下降。

• notable

  Highlights something that stands out and deserves attention or praise, often used for achievements, features, or people; more positive and descriptive than significant.

  强调某事物突出、值得关注或称赞，常用于成就、特色或人物；语气比significant更积极、更具描述性。

  The restaurant is notable for its use of locally grown vegetables.

  这家餐厅以使用本地种植的蔬菜而闻名。

• momentous

  Describes an event or decision so important that it changes the course of someone's life or of history; stronger and more dramatic, rarely used for small or statistical changes.

  形容一个事件或决定极其重要，足以改变一个人的人生轨迹或历史进程；语气更强烈、更具戏剧性，很少用于形容微小或统计上的变化。

  Landing on the moon was a momentous achievement for humankind.

  登月是人类历史上一个重大的成就。

Significant, notable, and momentous all mean important, but differ in strength. Significant describes a measurable or clear amount of importance, common in formal writing. Notable highlights something that stands out and deserves attention. Momentous is strongest, an event so important it changes a life.

这三个词都表示“重要”，但程度和语气不同：significant强调可测量或明显的重要性，notable强调值得关注或称赞的突出之处，momentous则强调对人生或历史进程有深远影响的重大程度，语气最强烈。这里不比较significant表示“意味深长的”（如significant look）的用法。