This post lists and defines words derived from the Latin noun terra, meaning “earth” or “land.”
Terra is used in several contexts in English but never on its own as a common noun. It is the name of an early Roman goddess associated with Ceres, the goddess of agriculture and maternity, and identified with the Greek goddess Gaia. It is also the Latin name for Earth and is widely used as such in science fiction; the adjective in usage associated with the proper noun is Terran. (The notion of populating another planet with Earth’s flora and fauna to facilitate colonization is called terraforming.) In addition, it refers to landmasses on planets and satellites, in combination with other classical names (such as Aphrodite Terra on Venus and Terra Cimmeria on Mars). In this context, the Latin plural terrae is employed to refer to more than one such feature.
“Terra firma” originally referred to outlying areas of the Republic of Venice as opposed to the city itself, which was built on a lagoon; now, it means “solid ground” and is used figuratively as well as literally to refer to having a steady, substantial footing. Terra-cotta, meanwhile, means “cooked earth” and is the name of a type of clay used for statuary, vases, and architecture, as well as the word for products made of the clay; it also refers to the brownish orange typical of the finished product.
The word is also associated with landmasses on Earth, as in the well-known phrase “terra incognita” (literally, “unknown land”), which refers to hypothetical places, and the more obscure “terra nullius” (essentially equivalent to “no man’s land”). Because these Latin phrases, at least, have been adopted into English, they need not be italicized.
Other words stemming from terra include terrain, which originally described equestrian training grounds but now pertains to a piece of land in general or the physical features of such. (That word is part of the phrase “all-terrain vehicle,” usually referred to by its initials, ATV.) It can be employed figuratively just as area is—for example, when describing a skill or topic one is unfamiliar with as “new terrain.”
Terrace, which referred in its Old French form to a platform built on a mound of earth, now describes a flat area, used for leisure, next to a building or to an artificially level section of a hillside where crops are grown, as well as a row of houses or a residential street, originally one located on a slope. It may also refer to any flat natural or constructed area. Terrace is also a verb describing formation of either general type of terrace.
Terrestrial is an adjective describing something pertaining to Earth or to land as opposed to water, air, or space; it also refers to the dense inner planets of the solar system as distinct from the large, gaseous outer planets. Extraterrestrial, originally an adjective alluding to something originating elsewhere than on Earth, is often employed to denote a being from another planet, especially a sentient one that is part of an alien civilization.
Terrene is an obscure alternative to the adjective terrestrial; a related adjective, subterranean (literally, “underground”), is much more familiar.
Territory refers in general to an area of indeterminate size; more specifically, it may pertain to a geopolitical area under government jurisdiction but not classified as a province, state, or other national subdivision. The word may be used figuratively as a synonym for the nonliteral use of terrain. (The idioms “come(s) with the territory” and “go(es) with the territory” refer to something being an inevitable aspect of a situation.) The adjectival form is territorial; both the noun and the adjective may refer to animal behavior related to protection of habitat.
A terrarium is a small indoor enclosure, usually made of clear glass or plastic, for observing animals and/or plants in a microcosm of their natural environment; the word is constructed on the model of aquarium. On a related note, the obscure adjective terraqueous means “consisting of both land and water.”
Another rare word stemming from terra is parterre, which describes an ornamental garden or the main floor of a theater. Better-known words that may not be easily recognized as being derived from terra include terrier, originally pertaining to a type of dog originally bred to pursue animals into burrows, and tureen, a word for a deep, covered bowl used for baking and/or serving soup or other foods or for a similar laboratory container.
Terrible and terror are unrelated words stemming from the Latin verb terrere, meaning “frighten,” and interrogate is from interrogare, consisting of the prefix inter- attached to the verb rogare, meaning “ask.”