‘需用’ is a compound noun meaning ‘required use’ or ‘necessary usage,’ emphasizing something that must be used for a specific purpose or function. The first character 需 (xū) means ‘to need’ or ‘require,’ carrying a sense of necessity or obligation; the second character 用 (yòng) means ‘to use’ or ‘usage.’ Together, they form a formal, slightly literary term indicating indispensable application—often in contexts where resources, tools, or biological functions are essential for survival, operation, or maintenance.

This term appears frequently in technical, agricultural, veterinary, or ecological descriptions—especially when discussing animals’ physiological needs (e.g., water, feed, shelter) or equipment required in animal husbandry. It is not commonly used in casual speech but appears in official documents, care guidelines, and scientific reports. Unlike the verb phrase ‘需要使用’ (xūyào shǐyòng), ‘需用’ functions exclusively as a noun and often modifies another noun (e.g., ‘需用物资’ — materials for required use).