proton

noun

pro·​ton ˈprō-ˌtän 

: an elementary particle that is identical with the nucleus of the hydrogen atom, that along with the neutron is a constituent of all other atomic nuclei, that carries a positive charge numerically equal to the charge of an electron, and that has a mass of 1.673 × 10⁻²⁷ kilogram

protonic

prō-ˈtä-nik 

adjective

Examples of proton in a Sentence

Recent Examples on the Web

Google tested its Trillium TPUs using a proton beam at UC Davis’ Crocker Nuclear Laboratory while the processors ran machine learning workloads. — Neetika Walter, Interesting Engineering, 24 Sep. 2026

New physics may only manifest at high-energy levels, the sort of energies that the LHC generates by slamming together protons at near light speed. — Robert Lea, Space.com, 21 Sep. 2026

In this new experiment, a proton beam acted as the cosmic ray, while the oxygen beam played the role of Earth’s atmosphere. — Jesse Liu, The Conversation, 14 Sep. 2026

Running back Cam Skattebo’s job is to run like a proton in a particle accelerator, but Dart’s certainly is not. — Andy Behrens, New York Times, 11 Sep. 2026

Word History

Etymology

Greek prōton, neuter of prōtos first — more at proto-

First Known Use

1920, in the meaning defined above

Phrases Containing proton

• proton pump inhibitor
• proton synchrotron

Rhymes for proton

• anton
• argon
• axon
• baronne
• baryon
• baton
• boron
• buisson
• bygone
• capon
• cardon
• chiffon

Kids Definition

proton

noun

pro·​ton ˈprō-ˌtän 

: an atomic particle that occurs in the nucleus of every atom and carries a positive charge equal in size to the negative charge of an electron

protonic

prō-ˈtän-ik 

adjective

Medical Definition

proton

noun

pro·​ton ˈprō-ˌtän 

: an elementary particle that is identical with the nucleus of the hydrogen atom, that along with neutrons is a constituent of all other atomic nuclei, that carries a positive charge numerically equal to the charge of an electron, and that has a mass of 1.673×10⁻²⁴ gram

protonic

prō-ˈtän-ik 

adjective