Any particle that obeys Bose-Einstein statistics but not the Pauli exclusion principle; all nuclei with an even mass number are bosons WordNet 3.0 & Open English WordNet

In particle physics, a boson is a subatomic particle whose spin quantum number has an integer value. Wikipedia

Particle that has integer spin. Wikipedia Disambiguation

Quantum system invariant by exchange of two identical instances Wikidata

A subatomic particle that obeys Bose–Einstein statistics. OmegaWiki

A particle with totally symmetric composite quantum states, which exempts them from the Pauli exclusion principle, and that hence obeys Bose-Einstein statistics. They have integer spin. Among them are many elementary particles, and some (gauge bosons) are known to carry the fundamental forces. Compare fermion. Wiktionary

Particle. Wiktionary (translation)