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

Its pores are large enough to allow the plasma particles to pass through to the electrocatalyst layer, meet the protons from the water, and drive the chemical reactions. — Georgina Jedikovska, Interesting Engineering, 17 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

Firstly, the signal indicates that WIMPs have a mass around 200 times greater than the mass of a proton. — Robert Lea, Space.com, 2 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