An Etymological Dictionary of Astronomy and Astrophysics

In → particle physics, any of postulated “point-like” particles from which are composed → quarks and → leptons. In other words, preon models assume there is a more fundamental kind of particle than those so far known. Different preon models consider different numbers and different natures of the preons.

See also: Coined by Jogesh Pati and Abdus Salam in 1974, from → pre- + → -on.