A formal, literary term for the very first beginning or origin of something, often used in historical or philosophical contexts. The word is rare in modern conversation.
The source of this river is said to be a small spring deep in the mountains.
The origin of the tea ceremony dates back to the Kamakura period.
Borrowed from Chinese 濫觴, based on the image of a great river’s source being so shallow that it can float only a wine cup. The expression consequently came to mean the source or beginning of something.