A particle with no spatial extent; specifically one used as an idealized approximation of a real particle, with its entire mass treated as if it were located at its centre of gravity.
Origin
Early 20th century.
Definition of point particle in US English:
point particle
noun
Physics
A particle with no spatial extent; specifically one used as an idealized approximation of a real particle, with its entire mass treated as if it were located at its centre of gravity.