pionium

noun — 2 senses

noun

Etymology From pion + -ium.

Chemistry, Natural sciences, Physical sciences, Physics an exotic atom equivalent to a hydrogen atom with the proton replaced by a pion

Natural sciences, Physical sciences, Physics an onium where the bound antiparticle-particle pair is a pion and an antipion.

Entry derived from the Wiktionary, under licence CC BY-SA 4.0 — list of authors.