wellspring

The source of a stream or spring.

A source.

A water-source; a fountainhead; a living spring.

Hence Figuratively, a perennial source of anything; a fountainhead of supply or of emanation.

A fountain; a spring; a source of continual supply.

The source of water for a stream, spring or well; a fountainhead; a wellhead.

A perennial source of anything; a fountainhead of supply or emanation; resource.

the source of water for a well

an abundant source