natural science 
(usually natural sciences)
noun [mass noun]
1A branch of science which deals with the physical world, e.g. physics, chemistry, geology, biology.In the natural sciences, biology and geology should be emphasized....
- The first is a scientific encyclopaedia covering logic, natural sciences, psychology, geometry, astronomy, arithmetic and music.
- In addition, all institutions have freshman introductory courses both in natural sciences and social sciences.
1.1The branch of knowledge which deals with the study of the physical world.Hence, physical or natural science is the study of material bodies that undergo change and are either in motion or repose....
- He won an open scholarship in mathematics and natural science to study at Trinity College, Cambridge.
- It is characteristic of him that his decision to study natural science and medicine was determined not so much by his reading as by his dreams.