Since half of all Red Line trains turn back there, you've probably heard the name "Grosvenor" spoken aloud even if you've never been there. Have you ever wondered why the S is either silent or pronounced in the wrong place?
The correct pronunciation for the station is "grove-nor", with no s-sound. Many, however, say "groves-nor", with the s-sound following the V, rather than preceding it.
The reason for this oddity goes back to 1066, but we're getting ahead of ourselves.
The station that eventually became Grosvenor appeared on early planning maps with the name "Pooks Hill" or "Parkside". The Pooks Hill location would've been just inside the Beltway. Parkside was closer to the chosen location, north of the I-495 interchange.
The station was mainly intended to be a park and ride, so proximity to the Beltway and the southern end of I-270 (then, I-70S) was the primary goal. There wasn't much in the area, so the station took the name of a nearby cross street, Grosvenor Lane.
When the station was finally sited during the design process, it was located farther north, likely to avoid the environmental impacts and constrained site closer to the Beltway. The station is actually located at the intersection of Rockville Pike and Tuckerman Lane, the next major east-west street north of Grosvenor Lane. For whatever reason, the Grosvenor name stuck.
So, what about the pronunciation? Well, Grosvenor Lane is also correctly pronounced "grove-nor", because it's named after a person: Gilbert Hovey Grosvenor.
Gilbert Grosvenor bought a tract of farmland along what is now Grosvenor Lane in 1912, moving to the farm from his urban home in Dupont Circle. Grosvenor Lane was named for him.
Gilbert Grosvenor left his mark on the country in more than just leaving his name to a Metro station. Grosvenor was heavily involved in the National Geographic Society, becoming its first full time employee in 1899 and eventually the director and president of the Society.
He's also considered the father of photojournalism. Though his work with National Geographic, he was instrumental in pressuring Congress to create the National Park Service in 1916.
Gilbert Grosvenor's surname can be traced all the way back to the Norman invasion of 1066.
Hugh d'Avranches was a councilor of William the Conqueror and after the successful invasion of England, Hugh became an Earl.
In William's court, Hugh was known as Hugh le Grand Veneur, Hugh the Master Huntsman. But he was overweight and gained the nickname "Le Gros Veneur," the Fat Huntsman.
The nickname was later anglicized to Grosvenor when it became a surname, and because the "s" in the French word "gros" was silent, it remained silent in the English version.
As a result, Grosvenor station has a silent "s".