headspring

1. A fountainhead; a source.

   the source of water from which a stream arises

2. (figuratively)A basis or foundation.

3. A move in which the gymnast places both hands on the mat with the top of the head about 6 inches in front, pushes off with the hands while flipping the legs overhead, and lands on the feet.

4. A spring that sits at the top of a mechanism, pushing the internal parts inward.

regular