An Earthquake is a sudden tremor or movement of the earth's crust, which originates naturally at or below the surface.The word natural is important here, since it excludes shock waves caused by French nuclear tests, man made explosions and landslides caused by building work. There are two main causes of earthquakes.n Earthquake is a sudden tremor or movement of the earth's crust, which originates naturally at or below the surface.
Definition of TANGRAM. : a Chinese puzzle made by cutting a square of thin material into five triangles, a square, and a rhomboid which are capable of being recombined in many different figures.See tangram defined for kids. ADVERTISEMENT.efinition of TANGRAM. : a Chinese puzzle made by cutting a square of thin material into five triangles, a square, and a rhomboid which are capable of being recombined in many different figures. See tangram defined for kids. ADVERTISEMENT.
1 The origin of the word âtangramâ is uncertain, and there are a variety of theories about it, including that it comes from an old English word âtramgramâ meaning puzzle or trinket. 2  Tangrams were originally made from glass, wood, ivory or turtle shell, and are now commonly made from plastic.