Definition of natural disaster : a sudden and terrible event in nature (such as a hurricane, tornado, or flood) that usually results in serious damage and many deaths The earthquake was one of the worst natural disasters of this century.
Synthesis, Chemical. the planned production of complex compounds from simpler compounds based on a knowledge of the reactantsâ chemical structure and reactivity. Chemical synthesis usually implies a sequence of several chemical processes (steps). In the early period in the development of chemistry, chemical synthesis was carried out mainly for inorganic compounds and was fortuitous in nature.
1 Organic synthesis, the chemical synthesis of organic compounds. 2  Total synthesis, the complete organic synthesis of complex organic compounds, usually without the aid of biological processes. 3  Convergent synthesis or linear synthesis, a strategy to improve the efficiency of multi-step chemical syntheses.