noun erf (US regional, Cape Colony, New York) A small inherited house-and-garden lot in a village or settlement. 0
noun erf (mathematics) error function. 0
noun erf a plot of land, usually urban, marked off for building purposes 0
noun acronym erf electrorheological fluid: a man-made liquid that thickens or solidifies when an electric current passes through it and returns to a liquid when the current ceases 0
