施行 means 'to put into effect' or 'to implement', especially in formal contexts involving laws, regulations, policies, medical treatments, or procedures. The character 施 (shī) conveys the idea of 'applying', 'carrying out', or 'administering', while 行 (xíng) means 'to carry out', 'to go', or 'to act'. Together, they emphasize deliberate, official action to activate or enforce something that has been planned or decreed.

This word is commonly used in government, legal, and healthcare settings — for example, when a new law takes effect, a surgical procedure begins, or a public health measure is launched. It carries a tone of authority and formality; you wouldn’t use it for everyday actions like 'making coffee' or 'sending a text'. It often appears with nouns like 法律 (fǎlǜ, 'law'), 政策 (zhèngcè, 'policy'), 手术 (shǒushù, 'surgery'), or 措施 (cuòshī, 'measure').