The name Rain is of English origin and is believed to have emerged as a given name during the late 20th century. It is derived from the word "rain," which refers to the condensed moisture that falls from the atmosphere in the form of drops.

While the name Rain does not have a long historical lineage, it is thought to have been inspired by the natural phenomenon of rain and its symbolism in various cultures. In many traditions, rain is seen as a symbol of fertility, renewal, and cleansing.

One of the earliest recorded instances of the name Rain can be found in the work of American author Richard Brautigan, who wrote a novel titled "Trout Fishing in America" in 1967. In the novel, one of the characters is named Rain.

Among the notable individuals who have borne the name Rain throughout history, one can mention:

1. Rain Pryor (born 1969), an American actress and comedian, daughter of renowned comedian Richard Pryor.
2. Rain Phoenix (born 1972), an American actress, musician, and singer, sister of the late actor River Phoenix.
3. Rain Brown (born 2002), an American reality television personality known for her appearance on the show "Alaskan Bush People."
4. Rain Wilson (born 1976), an American actress known for her roles in films such as "The Cooler" and "Reign Over Me."
5. Rain Dove (born 1989), an American model, actor, and activist known for their work in promoting gender inclusivity and challenging traditional gender norms.

While the name Rain may be relatively modern in its usage as a given name, it has gained popularity in recent decades, perhaps reflecting a growing appreciation for nature-inspired names and the symbolism associated with the natural phenomenon of rain.