用以

用以 is a prepositional phrase meaning 'to use for' or 'to be used for.' It indicates the purpose or function of something, often in formal or written contexts.

The character 用 (yòng) means 'to use,' while 以 (yǐ) functions as a classical preposition meaning 'for' or 'in order to.' Together, they form a fixed expression that emphasizes the intended use or purpose of an action or object.

用以 is commonly found in official documents, academic writing, and technical texts. It conveys a sense of intentionality and specificity, making it suitable for describing the function of tools, methods, or systems. It is less common in everyday spoken language but remains important in formal communication.