Janessa is a form of Jane, possibly influenced by Vanessa. Jane originates in Hebrew language and means "God is merciful". It is ultimately derived from the Hebrew masculine name Yochanan, thus it has the same origin as many other names, including Joan and Hannah. Jane has always been one of the most popular names in the English-speaking countries, and in different spelling all over the world. The famous bearer was the English novelist Jane Austen, and the name was also popularized in Charlotte Bronte's Jane Eyre. Jane functions as a surname as well.