(physics) Any of three semistable mesons, having positive, negative or neutral charge, composed of up and down quarks/antiquarks.

plural of pion

(nonce word) A word of disputed meaning; perhaps, abounding in marsh marigolds.

(physics, of a theory) That includes pions

A theoretical type of antimatter rocket which uses proton-antiproton fuel, and magnetic rocket funnels to direct the π-on exhaust. The pi meson particles are created by the matter-antimatter annihilation of protons and antiprotons.

plural of pion rocket

One who goes before, as into the wilderness, preparing the way for others to follow. / A person or other entity who is first or among the earliest in any field of inquiry, enterprise, or progress.

(transitive) To be the first to do or achieve (something), preparing the way for others to follow.

(physics, chemistry) an exotic atom equivalent to a hydrogen atom with the proton replaced by a pion / (physics) an onium where the bound antiparticle-particle pair is a pion and an antipion.

(US) A Utah state holiday celebrating the arrival of Mormon pioneers in what became Salt Lake City, Utah, in 1847.