Nanoscience and nanotechnology are recent advancement in the field of science and technology. Nanoscience is not just microtechnology on a smaller scale; it is much more than a mere improvement on previous forms of technology. Nanoscience is a completely new production process in a molecular world, opening up possibilities far beyond what we have known before. Researches in nanotechnology have great impact on existing knowledge. And a revolution is expected in all fields of science-medicine, physics, chemistry, biotechnology etc. in near future. This dictionary compiles major relevant terms pertaining to the nanoscience/nanotechnology. The description and definitions are drawn from different authoritative sources to make it a dependable reference tool.