Meso refers to a prefix meaning "middle" or "intermediate." It is often used in various scientific and academic contexts, such as in the term Mesoamerica, which describes a historical region in Central America known for its ancient civilizations, including the Maya and Aztec. The prefix can also be found in biology, where it denotes structures located between two other layers, such as in mesoderm, one of the three primary germ layers in embryonic development. In geology, "meso" can refer to the mesozoic era, a significant period in Earth's history that lasted from about 252 to 66 million years ago, known for the dominance of dinosaurs. Additionally, in the context of materials science, "meso" can describe materials with a size range between micro and macro, often referred to as mesoporous materials, which have unique properties useful in various applications, including catalysis and drug delivery.