Main Entry: me·son

Pronunciation: \ˈme-ˌzän, ˈmā-, ˈmē-, -ˌsän\

Function: noun

Etymology: International Scientific Vocabulary mes- + ²-on

Date: 1939

: any of a group of fundamental particles (as the pion and kaon) made up of a quark and an antiquark that are subject to the strong force and have zero or an integer number of quantum units of spin

— me·son·ic \me-ˈzä-nik, mā-, mē-, -ˈsä-\ adjective