It is the name of the eleventh letter of the Greek alphabet. It's equivalent to our L. In Physics represents the distance between two points in a repeating wave. Wavelength . It can also be the radioactive constant of an isotope. The term Lamda is used in many branches of science. For example, in Medicine, lambda is the craniometric point located at the intersection of sagittal suture and lambdoid suture. In Cosmology it is the Cosmological Community (Albert Einstein's Theory of Relativity). In Microbiology it is a type of viurs (Fago lamda ) used to replicate DNA. In Astronautics, type of Japanese rockets. It is also used in Chemistry, Metametics, etc.