What does "alpha particle" mean?

A doubly positively charged nucleus of a helium-4 atom (consisting of two protons and two neutrons), emitted as a consequence of radioactivity.

Alpha particle

Common synonyms include: antibaryon, antilepton, antimeson, atomic nucleus, atomic particle, aurora particle.

noun

noun ·Rare ·Advanced level

Noun

1
A doubly positively charged nucleus of a helium-4 atom (consisting of two protons and two neutrons), emitted as a consequence of radioactivity.
"Holonyms: alpha ray, alpha radiation"
2
a positively charged particle that is the nucleus of the helium atom; emitted from natural or radioactive isotopes wordnet

"Holonyms: alpha ray, alpha radiation"