meso-, mes-, mesi-

(Greek: middle, intermediate; close to a center line; between)

mesothermy
1. A reference to organisms that live in temperate zones.
2. A plant that lives in intermediate temperature conditions, with a minimum of 22°C in the warmest month and a range of 6-18°C in the coldest month.
mesothoracic
A reference to the middle segment of the thorax in an insect, the middle region of the body of an insect, or that region which bears the legs and wings.
mesothorax
The middle of the three segments of an insect's thorax, from which the middle pair of legs and first pair of wings grow.
mesotil
1. A partially plastic or somewhat brittle material derived from the chemical weathering of glacial debris beneath a partially drained area.
2. A semiplastic or semifriable derivative of chemically weathered till; forms beneath a partially drained area.

Semifriable refers to that which is easily broken into small fragments or reduced to powder while till is unstratified soil deposited by a glacier which consists of sand and clay and gravel and boulders mixed together.

mesotraphent
A reference to aquatic plants existing in water bodies with intermediate nutrient concentrations.

—The only source found for this word is the
The Cambridge Illustrated Dictionary of Natural History;
Cambridge University Press; New York; 1987; page 233.
mesotrophic
Having intermediate levels of primary productivity.

Referring to water areas having intermediate levels of the minerals required by green plants.

mesotropic
1. Conditions changing from wet or dry to medium with reference to a succession of plants.
2. Located toward the median plane of a cavity; such as, the abdomen.
3. A vertical plane through the midline of the body that divides the body into right and left halves.
mesovarium
The fold of peritoneum (smooth serous, or delicate, membrane which lines the cavity of the abdomen) connecting the ovary (organ in female animals that produces eggs and the sex hormones estrogen and progesterone) with the wall of the abdominal cavity.
Mesozoa (pl) (noun)
The phylum of invertebrates comprising the mesozoans: The Mesozoa include the parasitic wormlike multicellular organisms sometimes considered to be intermediate in complexity between protozoans and metazoans.

The Mesozoa constitute the small phylum of ciliated worms, which are endoparasitic in marine invertebrates.

The small phylum of ciliated, multicellular animals are found as endoparasites (parasites living in the internal organs of animals) in various marine invertebrates.

They are characterized by having a solid, two-layered body lacking skeletal, muscular, nervous, digestive, and excretory elements.

They are all obligate parasites and their simple organization may be secondary, a result of parasitic adaptation and they are found on both sides of the Atlantic, and on the west coast of America.

Mesozoic (proper noun)
The geologic era between the Paleozoic and the Cenozoic eras: The Mesozoic is the second of the earth's three major geologic eras of Phanerozoic time and the interval during which the continental landmasses as known today were separated from the supercontinents "Laurasia" (North America and Eurasia) and "Gondwana" by the continental drift.

The Mesozoic is divided into three time periods: the Triassic (245-208 Million Years Ago), the Jurassic (208-146 Million Years Ago), and the Cretaceous (146-65 Million Years Ago).

The Mesozoic occurred before the Cenozoic and after the Palaeozoic periods and was marked by the development of the ancestors of the major plant and animal groups that exist today and the extinction of the dinosaur that suddenly occurred at the end of the Cretaceous period.

Mesozoic means "middle animals", and is the time during which the world fauna changed drastically from that which had been seen in the Paleozoic.

Dinosaurs, which are perhaps the most popular organisms of the Mesozoic, evolved in the Triassic, but were not very diverse until the Jurassic. Except for birds, dinosaurs became extinct at the end of the Cretaceous period. Some of the last dinosaurs to have lived are found in the late Cretaceous deposits of Montana in the United States.

The Mesozoic was also a time of great change with terrestrial vegetation. The early Mesozoic was dominated by ferns, cycads, ginkgophytes, bennettitaleans, and other unusual plants. Modern gymnosperms, such as conifers, first appeared in their current recognizable forms in the early Triassic.

By the middle of the Cretaceous period, the earliest angiosperms had appeared and began to diversify, largely taking over from the other plant groups.

mesozooid (s) (noun), mesozooids (pl)
A marine parasite of the phylum Mesozoa: A mesozooid is a kind of bryozoan heterozooid that makes slim and narrow tubes called "mesozoopecia" or "mesopores" which are subdivided internally by various tightly spaced diaphragms that reveal minute polygonal openings.
mixomesohaline (adjective) (not comparable)
A reference to brackish water: Mixomesohaline describes salty water containing from 5 to 18 parts per thousand of dissolved salts.