proton

The story

1. Proto-Indo-European*per-der.?
2. Proto-Indo-European*pér
3. Proto-Indo-European*pró
4. Ancient Greekπρό (pró)
5. Ancient Greekπρῶτον (prôton)
6. English todayproton

Learned borrowing from Ancient Greek πρῶτον (prôton), neuter of πρῶτος (prôtos, “first”). (physics): Coined by New Zealand-British scientist Ernest Rutherford in 1920, in analogy with electron (1891), and with an additional intention of honoring English chemist William Prout. Analyzable as proto- + -on (anatomy): A translation of German Anlage (“fundamental thing”) based on Aristotle’s phrase ἡ πρώτη οὐσία τὸ πρῶτον (hē prṓtē ousía tò prôton).

First known use, by meaning

• from 1920 A positively charged subatomic particle forming part of the nucleus of an atom and determining the atomic number of an element, composed of two up quarks and a down quark.
• from 1920 The atomic nucleus of protium (hydrogen-1)
• 1893–1903 Synonym of primordium.