What is the meaning of Meson?

The mesial plane dividing the body into similar right and left halves.

A member of a group of subatomic particles having a mass intermediate between electrons and protons. (The most easily detected mesons fit this definition.)

An elementary particle that is composed of a quark and an antiquark, such as a kaon or pion. (Mesons composed of rarer quarks are much heavier.)

meson

accusative singular of meso

Alternative spelling of méson

house

Source: wiktionary.org