RECOMMENDED LESSONS: Runoff Runoff is precipitation that did not get (infiltrated) absorbed into the soil, or did not evaporate, and therefore made its way from the ground surface into places that water collect. Runoff causes erosion, and also carry chemicals and substances on the ground surface along to the rivers where the water ends up.
Noun. 1. obelisk-a stone pillar having a rectangular cross section tapering towards a pyramidal top. pillar, column-a vertical cylindrical structure standing alone and not supporting anything (such as a monument).
monolith (plural monoliths) 1  A large single block of stone, used in architecture and sculpture. 2012 January 1, Henry Petroski, âThe Washington Monumentâ, in American Scientist, volume 100, number 1, page 16: The Washington Monument is often described as an obelisk, and sometimes even as a âtrue obelisk,â even though it is not.