a hypothetical subatomic particle having only one type of magnetic charge, the magnetic analogue of an electrically charged particle; it has only one magnetic pole instead of the two observed in all common magnetic object; -- it was still not observed as of 1998.

A massive elementary particle carrying a free north or south magnetic pole, postulated by some theories of elementary-particle physics but as yet unobserved.

a hypothetical particle with a single magnetic pole instead of the usual two

a separate north or south pole particle by itself (half a magnet, so to speak), a consequence predicted by the grand unified theories (GUT)

A single hypothetical magnetic pole. Monopoles have not been detected yet.

In physics, a magnetic monopole is a hypothetical particle that may be loosely described as "a magnet with only one pole" (see electromagnetic theory for more on magnetic poles). In more accurate terms, it would have net magnetic charge. Interest in the concept stems from particle theories, notably Grand Unified Theories and superstring theories, that predict either the existence or the possibility of magnetic monopoles.