the world > the earth > land > landscape > low land > hole or pit > [noun] > caused by erosion or water > specifically by spring or geyser (3)
†(a) a hole or cavity formed by a spring where it rises; (formerly also) a well (obsolete); (b) (in later use) a small hole or crater formed on a…
a hole, cavity, or pond formed by a spring where it rises; cf. spring pit n. (a).
transferred. The tubular outlet of a geyser.