The spelling of the name Vanessa is commonly mispronounced and misspelled as "Vannesa". The correct pronunciation is \vəˈnɛsə\ with the stress on the second syllable. The origin of the name Vanessa is believed to come from the name of an Irish goddess, and it wasn't until the 18th century that the name was introduced as a given name. The spelling "Vanessa" is the conventional spelling and should be used to prevent confusion and ensure accuracy in written communication.
The name "Vanessa" has a rather interesting etymology. It was coined by the Irish author Jonathan Swift in his poem "Cadenus and Vanessa", written in 1713. Swift invented the name as a pseudonym for his real-life friend and lover, Esther Vanhomrigh. He combined the initial syllables of her last name, "Van", with the name "Essa", derived from the classical Greek name "Esfhe", meaning "butterfly". Therefore, the name "Vanessa" holds its origins in Swift's literary creation.