geo-, ge- +

1. The response of a plant to gravity, as evidenced by growing patterns: Geotropism can be explained as the downward root growth and growth curvature.
2. Plant growth or movement in response to gravity: Primary roots (tap roots) grow vertically towards gravity (positive geotropism) whereas primary shoots grow vertically away from gravity (negative geotropism), though the direction of shoot growth may also be modified by light.

An organism that becomes a temporary member of the soil fauna: Some bacteria can be found in a soil stratum of which it is not normally a resident, also known as a geoxene

A situation where an organism becomes a temporary or an accidental member of soil fauna: Jane tried to find some information on geoxeny and found out that some life forms thrived only as non-permanent residents in the soil.

A plant having woody stems arising from an underground woody rhizone: In his book about plants, Jeff found out that some plants were known to be geoxyls because the rhizones beneath the soil produced stalks or branches that were of a woody nature.

A person who studies geological phenomena involving the action of ice: Mr. Carpenter was an expert glacialist who attributed the phenomena of the geological drift to glaciers.

A line on a spheroid or a reference ellipsoid (circular form): A graphic meridian links the points possessing the same astronomical latitude.

A geologists who divides all time since the formation of the earliest known rocks (about four billion years ago) into four major divisions: Precambrian, Paleozoic, Mesozoic, and Cenozoic eras: A historical geologis maintains that each era, except the Cenozoic, ended with profound changes in the disposition of the Earth's continents and mountains and was characterized by the emergence of new forms of life.

Broad cyclical patterns, which run through all historical geology, include a period of mountain and continent building followed by one of erosion, and then by a new period of elevation.

A study of the historical development of the Earth from the examination of its rocks: In historical geology, the rocks are analyzed in order to determine their structure, composition, and interrelationships and are examined for remains of past life.

Historical geology includes paleontology, the systematic study of past life forms, stratigraphy, layered rocks and their interrelationships, as well as the locations of ancient land masses and their boundaries, and geologic mapping, the superimposing of geologic information upon existing topographic maps.

The science dealing with the occurrence and distribution of underground water; hydrology; geohydrology: Hydrogeology studies the movement of subsurface water through rocks and the effect of moving water on rocks, including their erosion.

Hydrogeology is also concerned with the physical, chemical, and biological features of groundwater.

A plant that grows in earth and in water: One example of a hydrogeophyte is the Lucky Bamboo that can thrive in both soil and water.

Regarding an organism that lives primarily beneath the surface of the ground, or that germinates with the cotyledons remaining in the soil: Examples of hypogean plants are the peanut and oak.

A hypogean beetle can exist in a stable habitat that has an unwavering temperature and a relatively high humidity.

1. Regarding something that has been formed by ascending fluids within the Earth: Hypogene ore or mineral deposits have been produced by rising solutions inside the planet...
2. Concerning a structure that has been formed beneath the Earth's surface: Hypogene rocks are ones that have been created or crystallised and are situated at depths below the surface of the Earth.

Regarding an organism that lives or germinates below the soil surface: The hypogeal origin of plant development, like seedlings, lessens the consequences of freezing or of conditions of dry surroundings.

A line or surface (usually imaginary) connecting points in the interior of the Earth having the same temperature: In class, Sam learned about isogeotherm curved lines inside the Earth that linked points having the same temperature.

A descriptive reference to a line or surface (usually imaginary) connecting points in the interior of the Earth having the same temperature; The students were asked to present isogeothermal lines showing the exact same degrees of hotness or coldness within the planet.