dipole

The word dipole refers to two poles and is used to describe electric fields and magnetic fields that are organized around two locations of opposite polarity. In contrast, multipole indicates more locations, e.g., some of each polarity. For example, a planet's magnetic field can be basically a dipole overall, yet in detail be multipole if there are spots on the surface where one or the other polarity is strong.

The word dipole has other related uses, such as to describe antennas (dipole antenna, which creates or senses a dipole electric field), and in mathematics as a subclass of coefficients of a multipole expansion.