The water cycle, also known as the hydrologic cycle or the H2O cycle, describes the continuous movement of water on, above and below the surface of the Earth. Although the balance of water on Earth remains fairly constant over time, individual water molecules can come and go, in and out of the atmosphere.
OBJ: Olusegun Obasanjo (president of Nigeria) OBJ: Official Black Jester (website)
Definition of OB. OB: Abbreviation for obstetrician or for obstetrics, the art and science of managing pregnancy, labor and the puerperium, the time immediately after delivery. Search MedTerms: