The meaning given for this English surname is a speculation. The Old English term wista referred to the amount of land needed to supply the needs of a village. In Sussex, it came to be used the same way we now use the term ''acre,'' that is, as a specific measure of land.
Our definition is informed by that of another English surname, Spencer, given those in charge of ''dispensing'' the goods of a feudal lord to his vassals. We speculate that a steward in charge of the wista or food supplying region of a municipality might have been called a ''wister'' or ''wistar.''
The Wistaria plant was named to honor American anatomist Caspar Wistar (1761- 1818) who sometimes spelled his name Wister. This alternate spelling of the name, so like other occupational nouns that became names (farmer, baker, carter, etc.) also supports our theory on Wistar's origins.