a pair of equal and opposite electric charges or magnetic poles separated by a small distance
"The scientist explained that water molecules act as dipoles because their positive hydrogen side is attracted to the negative oxygen side."
an aerial half a wavelength long consisting of two rods connected to a transmission line at the center
"The technician had to fabricate a custom dipole by joining two aluminum rods at their centers and attaching them directly to the coaxial feed line."
any object (such as a magnet, polar molecule or antenna) that is oppositely charged at two points (or poles)
"The water molecule acts as a dipole because its oxygen end carries a partial negative charge while the hydrogen ends are partially positive."