operation

Compared meaning: a medical operation or surgical procedure (noun).

比较义项：手术（名词）。

• surgery

  Surgery is the general, often uncountable term for medical treatment that involves cutting into the body; it names the type of treatment or field rather than one single event.

  surgery是更笼统、常作不可数名词的说法，指切开身体进行治疗的这类医疗手段，而不是指某一次具体的手术事件。

  She needed surgery to fix her broken arm after the fall.

  摔倒后，她需要接受手术来治好摔断的手臂。

• operation 本词

  Operation refers to one specific surgical procedure and is a countable noun (an/the operation), emphasizing the single act performed on a particular occasion.

  operation指某一次具体的手术，是可数名词（an/the operation），强调在某个场合实施的这一次手术行为。

  The hospital performed a difficult operation yesterday.

  医院昨天做了一台高难度的手术。

Both words can mean medical treatment that involves cutting into the body. Surgery is the general, often uncountable word, naming the type of treatment or field rather than one event. Operation is countable and refers to one specific procedure performed on a particular occasion.

这两个词都可表示“手术”，但surgery更笼统，常作不可数名词，指切开身体进行治疗的这类医疗手段或过程；operation则指某一次具体实施的手术，是可数名词，强调在某个场合发生的这一次行为。这里不比较surgery在英式英语中表示“诊所、诊室”的用法，也不比较operation表示“运作、操作、运营”等更宽泛的意思。