mature

Compared meaning: fully grown or having reached adulthood (adjective).

比较义项：成年的，发育完全的（形容词）。

• adult

  Adult is the neutral, formal term marking someone who has reached full legal or biological growth; it classifies an age category (adult education, adult male) rather than judging personality or behavior.

  adult是中性、正式的说法，指某人已达到法定或生理上的完全成年；它用于划分年龄类别（比如成人教育、成年男性），而不是评价性格或行为。

  Only adult passengers may sit in the exit row on this flight.

  在这趟航班上，只有成年乘客才可以坐在安全出口旁的座位。

• mature 本词

  Mature stresses sensible, adult-like behavior or emotional development, not just age; it is graded (more mature, mature for her age) and can also describe physical ripeness or full growth.

  mature强调懂事、成熟的行为或心智发展，而不只是年龄；它有程度变化，比如可以说更成熟，或以某人的年龄来说很成熟，也可以用来形容发育完全或水果等成熟。

  She's surprisingly mature for a ten-year-old and rarely throws tantrums.

  以一个十岁孩子来说，她出乎意料地成熟，很少乱发脾气。

• grown

  Grown is an informal, everyday word stressing that physical growth is complete, especially in fixed phrases like a grown man or woman; it sounds casual and slightly judgmental compared with adult.

  grown是较口语化的日常用词，强调身体已经长大、发育完成，常见于“成年男子”“成年女子”这类固定搭配中（如a grown man）；和adult相比，它听起来更随意，有时还带一点评判意味。

  He's a grown man now and should cook his own meals.

  他现在已经是个成年男人了，应该自己做饭。

Adult, mature, and grown can all describe someone fully grown. Adult is the neutral, formal term for legal or biological age. Mature stresses sensible, adult-like behavior, not just age. Grown is informal, stressing that physical growth is complete, as in a grown man or woman.

这三个词都可以表示“已经长大、成年的”，但语气和场合不同：adult是中性的法律或生物学年龄分类，mature强调心智或行为上的成熟，grown则是口语化地强调身体已经长大。这里不比较mature用作动词“变得成熟”和grown作为grow的过去分词“生长”的用法。

Compared meaning: to become fully developed or ready (verb).

比较义项：成熟（动词）。

• mature 本词

  General verb for people, animals, or abstract things becoming fully grown or developed; not limited to food, and often used about emotional or physical growth.

  泛指人、动物或抽象事物变得发育完全或成熟，不限于食物，常用于描述情感或身体上的成长。

  Some kids mature emotionally much earlier than others their own age.

  有些孩子在情感上比同龄人成熟得早得多。

• ripen

  Narrow verb used only for fruit, vegetables, or crops becoming ripe — sweeter, softer, and ready to eat.

  用法较窄，只用于水果、蔬菜或农作物变得成熟——变甜、变软、可以食用。

  These tomatoes need another few days on the windowsill to ripen.

  这些番茄还需要在窗台上放几天才能成熟。

Mature and ripen both mean to become fully developed. Mature is general: people, animals, or abstract things becoming grown, often emotionally. Ripen applies only to fruit, vegetables, or crops becoming sweet, soft, and ready to eat. Mature's due date sense for bonds is not compared.

这两个词都可以译成“成熟”，但使用对象不同：mature多用于人、动物或抽象事物，指长大、发育完全或变得成熟；ripen只用于水果、谷物等农产品，指变甜、变软、可以食用。此外，mature还有“（票据、债券等）到期”的义项，这里不作比较。