Pronunciation: [mˈiːsə͡ʊ] (IPA) 
The word "meso" can be spelled with three letters: M-E-S-O. It is pronounced with the IPA phonetic transcription /ˈmɛs.oʊ/. The first syllable, "mes," is pronounced with a short "e" sound followed by an "s" sound. The second syllable, "o," is pronounced with a long "o" sound. "Meso" is a prefix that means "middle" or "intermediate" and is often used in words related to biology, such as "mesoderm" or "mesothelium."
Meso is a prefix derived from the Greek word "mesos," meaning middle or intermediate. As a prefix, it is used to describe something that is situated or occurring in the middle, intermediate, or mid-sized range. It denotes a state or quality that falls between two extremes.
In the field of biology, the prefix meso- is often used to refer to a middle anatomical or morphological structure. For instance, mesoderm is the middle layer of cells in an embryo, located between the outer ectoderm and inner endoderm. Similarly, mesomorph is a somatotype characterized by a body build that is neither extremely lean nor excessively muscular, but rather has moderate muscle mass and good overall proportionality.
In geography, the prefix meso- is commonly employed to describe middle-sized geographical features. For instance, mesoclimate refers to the climatic conditions of a relatively small area, such as a valley or a forest, which differ from the surrounding macroclimate. Mesopause is the boundary between the mesosphere and the thermosphere in Earth's atmosphere, signifying the middle region of this atmospheric layer.
The term "meso" can also be used in some industries, such as mesoionic, which refers to a class of organic compounds that have a structure intermediate between usual ionic and covalent compounds, possessing both characteristics.
Overall, the prefix meso- conveys the notion of middle, intermediate, or in-between, depicting a state, structure, or concept that lies between two extremes or varying scales.
The word "meso" has its roots in the Greek language. It comes from the Greek prefix "meso-" (μεσο-), which means "middle" or "intermediate". This prefix is commonly used in scientific and technical contexts to denote something that is in the middle, intermediate, or between two extremes. For example, in biology, "mesoderm" refers to the embryonic germ layer that is positioned between the ectoderm and endoderm. Similarly, in meteorology, "mesosphere" describes the atmospheric layer located between the stratosphere and thermosphere.
