Name invented by Jonathan Swift (1667–1745) for his friend Esther Vanhomrigh. It seems to have been derived from the first syllable of her (Dutch) surname, with the addition of the suffix -essa (perhaps influenced by the first syllable of her given name). The name became fairly popular in the 20th century, being borne for example by the actress Vanessa Redgrave (b. 1937).
German, Jewish (Ashkenazic), and French (Alsace-Lorraine): from Middle High German fūst ‘fist’, presumably a nickname for a strong or pugnacious person or for someone with a club hand or other deformity of the hand.