The privet bush is a common, suburban plant, which is used to create neat hedges around many English gardens. Rowling used this plant as the street name to denominate "both suburbia and enclosure, the associations with both suburbia and enclosure, the Dursleys being so smugly middle
class, and so determinedly separate from the wizarding world." (pm)
A privet is a shrub of the olive family, with small white heavily scented flowers and poisonous black berries.