Definition of "proton"
proton
noun
plural protons
(physics) 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.
Quotations
The dance of the electrons about the prota, each electron and each proton consisting of a series of waves occupying the whole of the limited universe and obeying the laws of nature as they pass, is known to all.
1931, C[harles] G[eorge] Crump, The Red King Dreams, 1946 - 1948, 24 Russell Square: Faber & Faber Limited, page 302
(obsolete, anatomy) Synonym of primordium
Quotations
It is a well authenticated fact that, in the case of section of a peripheral nerve, the nuclei of the sheath of Schwann pass to the centre of the lumen and form the protoplasmic prota of the segments of the new nerve […]. From studies of the development of the olfactory organs in reptiles, as reported briefly in earlier numbers of this Journal, the writer has been abundantly convinced of the truth of Beard’s statement that the olfactory prota arise from the skin […].
1898 July, “Contributed Articles”, in C[larence] L[uther] Herrick, editor, The Journal of Comparative Neurology: A Quarterly Periodical Devoted to the Comparative Study of the Nervous System, volume VIII, number 1; 2, Granville, Oh.: […] C[harles] Judson Herrick; […], pages 27 (C. L. H., […]) and 32–33 (C. L. H.; G[eorge] E[llett] Coghill, […])
This paper constituted the proton (the primordium, or ‘Anlage,’ if you prefer) of my own subsequent contributions, and likewise, so far as I knew at the time, of the simplified nomenclature in America.
1898 December 28, Burt G[reen] Wilder, “Some Misapprehensions as to the Simplified Nomenclature of Anatomy”, in Proceedings of the Eleventh Annual Session of the Association of American Anatomists, […], Washington, D.C.: Beresford, […], published 1899, page 23
a, b. Prota of primitive segments (protovertebræ). […] These soon become partially constricted off from the fore-brain, their narrow pedicles—the optic stalks—being the prota of the optic nerves. The dorsal wall of the fore-brain continues to grow forward and upward from the rest of the vesicle, and soon forms a fourth ventricle or permanent fore-brain, the proton of the cerebral hemispheres. […] By the sixth week the otocyst has been converted by a fold into two portions—a dorsal part—the utriculus, from which three projections arise, the prota of the semicircular canals (Fig. 91), and a ventral part, the sacculus, from the anterior end of which the cochlea is developed. […] These are the Müllerian ducts, the prota of the female internal organs of generation. […] The cords acquire a lumen and become the prota of the seminiferous tubules.
1899, Walter P[orter] Manton, “Menstruation—Ovulation—Development of the Ovum”, in Charles Jewett, editor, The Practice of Obstetrics, New York, N.Y., Philadelphia, Penn.: Lea Brothers & Co., part II (Physiology of Pregnancy), pages 84, 97, 104, 111, and 112