acute

Compared meaning: sharp, intense, or piercing (adjective).

比较义项：形容尖锐、强烈的性质或感觉（形容词）。

• sharp

  Sharp is the general word for an object having a fine edge or point, like a knife; unlike the others, it names a physical property, not a felt sensation or sound.

  sharp 是通用词，指物体本身具有锋利的边缘或尖端（如刀），与其他几个词不同，它描述的是物体的物理性质，而不是一种被感知到的感觉或声音。

  The chef keeps his knives sharp so they cut vegetables cleanly.

  厨师把刀磨得锋利，这样切菜才干净利落。

• acute 本词

  Acute describes the intensity of a sensation, especially pain or a medical condition, meaning very sharp in effect; it is not used for physical blades or sounds.

  acute 描述一种感觉（尤其是疼痛或病症）的强烈程度，意为“效果上非常尖锐”；它不用于形容刀刃等实物或声音。

  The doctor said her stomach pain was acute and needed immediate attention.

  医生说她的胃痛很尖锐，需要立即就医。

• piercing

  Piercing describes a sound, such as a scream or alarm, that is loud, high-pitched, and sharp enough to hurt the ears; it is not used for pain or blades.

  piercing 用来形容尖叫、警报等又响又尖、刺耳到让人耳朵难受的声音；不用于形容疼痛或刀刃。

  The piercing scream from the alley made everyone stop and look.

  巷子里传来一声尖锐刺耳的尖叫，让每个人都停下脚步张望。

• stabbing

  Stabbing describes a sudden, sharp pain that feels like being pierced with something pointed; it is used only for pain, more vivid and informal than acute.

  stabbing 形容一种突然而尖锐的疼痛，感觉就像被尖锐的东西刺了一下；它只用于疼痛，比 acute 更形象、更口语化。

  He suddenly felt a stabbing pain in his chest and sat down quickly.

  他突然感到胸口一阵刺痛，猛地坐了下来。

These four words relate to sharpness, but apply differently. Sharp describes a physical edge, like a knife. Acute describes intense sensations, especially pain. Piercing describes a loud, high-pitched sound that hurts the ears. Stabbing describes a sudden, sharp pain, like being pierced.

这几个词都带有“尖锐”的意味，但适用领域不同：sharp 指物体本身锋利，acute 和 stabbing 都可形容疼痛（acute 偏医学、强调强烈，stabbing 偏口语、强调突然），piercing 则专指声音尖锐刺耳。学习者容易把 sharp 泛用到疼痛或声音的场合，应根据具体对象选用更贴切的词。

Compared meaning: how serious or dangerous something is (adjective).

比较义项：严重的／危险的程度（形容词）。

• acute 本词

  Describes pain, illness or a problem that is sudden and intensely felt, often medical; focuses on intensity rather than danger or long duration.

  指疼痛、疾病或问题来得突然且感觉强烈，多用于医学语境；强调程度剧烈，而非危险性或持续时间长。

  The sudden acute pain in his chest sent him straight to the emergency room.

  他胸口突然一阵剧痛，使他径直被送往急诊室。

• critical

  Describes a situation at a dangerous turning point where the outcome, often life or death, hangs in the balance and immediate action is needed.

  指情况到了危险的转折点，结果（往往关乎生死）悬而未决，需要立即采取行动。

  The patient's condition turned critical overnight, and doctors rushed to operate.

  病人的病情一夜之间转为危重，医生们赶紧进行了手术。

• serious

  The plainest, most general word for anything bad or worrying enough to need attention; weaker than critical or dire and usable in almost any context.

  是最平实、最通用的词，可用来形容任何严重到需要关注的坏事；语气比critical或dire弱，几乎适用于任何语境。

  The doctor said her injury was serious but not life-threatening.

  医生说她的伤势严重，但没有生命危险。

• dire

  The strongest and most dramatic of the four, describing an extremely serious situation, warning or consequence, often just before disaster strikes; more formal in register.

  四个词中语气最强烈、最具戏剧性，形容极其严重的处境、警告或后果，往往就在灾难降临之前；语域更正式，常与warning、consequences、straits等词搭配。

  Scientists issued a dire warning about the dangers of ignoring climate change.

  科学家就忽视气候变化的危害发出了极其严重的警告。

Acute, critical, serious, and dire all describe how bad something is. Acute means sudden and intense pain. Critical means a dangerous turning point. Serious is the general word for anything bad. Dire is the strongest, describing near disaster. Other senses of these are not compared.

这四个词都能表示“严重”，但严重程度、语域和典型搭配不同，中国学生容易混淆。这里不比较critical的“爱批评的”义项、serious的“认真的、不开玩笑的”义项，以及acute的“敏锐的”义项。