A place, person, or thing from which something originates or can be obtained. The river is the main source of water for the village.
A person or document that provides information. The journalist refused to reveal her source for the story.
A spring or fountainhead from which a stream or river flows. We hiked to the source of the river to see where it began.
A point or body that emits radiation, waves, or energy. The X-ray source must be carefully shielded.
Computing: the original human-readable code of a software program from which machine code is compiled or interpreted. The developers released the game's source under an open-source license.
Computer programming: the human-readable code of a program, usually stored in textual files, from which object or executable code is produced. Make sure you commit the source to the repository before building the binary.