quadrium

quadrium (uncountable)

1. (education) Synonym of quadrivium
   • 1861, William Howitt, John Cassell's illustrated history of England:

     Church music was carefully taught at the universities. IT was of the four sciences of the quadrium, and was a means of promotion in the church and colleges.

   • 1997, Timothy J. Reiss, Knowledge, Discovery and Imagination in Early Modern Europe:

     He describes how by the late fifteenth century the language arts of the trivium had come to seem useful only for communication, teaching and public debate, and how humanists turned to the mathematical arts of the quadrium - including music - to enable new means and methods of discovery.

   • 2014, Andreas Nordin, Transnational Policy Flows in European Education:

     The classical curriculum distinguishes between trivium and quadrium to classify knowledge fields in education. Trivium deals with the disciplines of language, grammar, rhetoric, dialectic and logic, while quadrium deals with the sciences of arithmetic, geometry and astronomy.

• trivium

From quadr- +‎ -ium.

quadrium (uncountable)

1. (physics, rare) A highly unstable synthetic isotope of the element hydrogen, ⁴₁H, having one proton and three neutrons.
   • 2011, “Kinetic Isotope Effects for the Reactions of Muonic Helium and Muonium with H₂”, in Science, volume 331, number 6016, page 448:

     The decimal character of 4.1 is a reminder that this is not a conventional H isotope such as quadrium, ⁴H, or other isotopes up to ⁷H, with lifetimes, when known in the 0.1 to 1 zs range.

quadrium (plural quadriums)

1. (physics, rare) A quadrium atom or nucleus.
   • 2014, Robert Godes, “Controlled Electron Capture and the Path Toward Commercialization”, in J. Condensed Matter Nucl. Sci., volume 13:

     The almost stationary ultra-cold neutron(s) occupies a position in the metal lattice where another dissolved hydrogen is most likely to tunnel in less than a nanosecond, forming a deuteron / triton / quadrium by capturing the cold neutron and releasing binding energy.

• tritium