The term "Novan" was used to describe a group of Human colonists who settled the planet Terra Nova and their descendants. The term was applied to these colonists in much the same way the term Martian was applied to those living on Mars. The Terra Nova colony was the first Human colony outside the Sol system, founded in 2078 by the SS Conestoga after a nine-year flight from Earth. The Novans were successful in establishing a fully-functioning community on a world in deep space so a second ship of colonists headed to Terra Nova was planned.
The Novans were not interested in sharing their home they had struggled to build. Led by a man named Mark Logan, the situation with Earth became severely strained, with Logan transmitting threats of violence upon any ships that would arrive in orbit of his planet. This was the last message received from Novans. Earth lost contact with them, and never launched a ship to investigate because of limited resources. The fate of the Novans remained a mystery.
In 2151, the Earth starship Enterprise NX-01 visited Terra Nova to discover the whereabouts of the apparently missing colony. They discovered the irradiated remains of the colony, and it was determined that the colony had been destroyed by an asteroid strike, which had scattered radioactive debris over the northern hemisphere. The Novans that survived the asteroid strike took refuge in underground caverns in order to avoid the radiation on the surface. They believed that Earth had attacked them with "poison rain" because they weren't willing to share their home. This belief was passed on to the next generations. The Novans considered Earth, and Humans, their enemy, and eventually had forgot or denied the idea their Human identity. When a landing party descended on the planet, Novan warriors attacked the "Human" intruders.
Eventually the Enterprise crew was able to gain the trust of the Novans, convincing them that Earth was not responsible for destroying the original colony. As the underground water supply the Novans used to survive had slowly become contaminated by the surface radiation, the Novan population was eventually relocated to a continent on the southern hemisphere that was unaffected by the fallout from the asteroid strike. (ENT: "Terra Nova")
The Novans had developed some special slang or expressions. Overside was the name of the planet's surface; while Underside were the underground caverns, their contemporary dwelling; they referred the Enterprise as a Skyship. To refer to hunger they used an expression such as Hollow Stomach; the ancestors were referred as Before Families; the radioactive devastation caused by the meteor was remembered as Poison Rain. Other terms were meaningful in the context of their cave-dwelling; they referred to to thought and mind as path and/or tracks, and lies were called shale, after the form of rock. When Jamin wanted no more to see the colonists' portraits and photographs on the viewscreen, he told Archer to bury his drawings. (ENT: "Terra Nova")