quadratic

• quadratick (obsolete)

From French quadratique (1765), from Latin quadrātus + -ique^[1] (English -ic), form of quadrō (“I make square”), from quādrus (“square”), ultimately from Proto-Indo-European *kʷetwóres (“four”), whence also Latin quartus (“fourth”).

• IPA^(key): /kwɒdˈɹætɪk/, /kwəˈdɹætɪk/

• Audio (Southern England):

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quadratic (not comparable)

1. Square-shaped.
2. (mathematics) Of a polynomial, equation or function, second-degree: involving the second power (square) of a variable but no higher powers, as ${\displaystyle ax^{2}+bx+c}$.
   • 2015 November 17, “Fast Fragmentation of Networks Using Module-Based Attacks”, in PLOS ONE‎^[1], →DOI:

     A linear or even a quadratic relation between the overall gain in efficiency η and the modularity Q would have been easily explained through S1 Fig, which shows a quadratic (inverse) relation between interedges fraction and modularity.

quadratic (plural quadratics)

1. (mathematics) A quadratic polynomial, function or equation.
   • 1809, Charles Hutton, The Philosophical Transactions of the Royal Society of London from Their Commencement in 1665 to the Year 1800, volume 3, page 41:

     If the binomial roots of a series of quadratics be squaredly squared, and those results be constant portions of the cube of the resolvend, and the dioristic limit; […]

Not to be confused with quartic (“degree four”). Both derive ultimately from Proto-Indo-European *kʷetwóres (“four”), with quadratic coming from “four-sided”, hence “square, two-dimensional, degree two”.

• square

• “quadratic”, in Webster’s Revised Unabridged Dictionary, Springfield, Mass.: G. & C. Merriam, 1913, →OCLC.
• William Dwight Whitney, Benjamin E[li] Smith, editors (1911), “quadratic”, in The Century Dictionary […], New York, N.Y.: The Century Co., →OCLC.
• “quadratic”, in OneLook Dictionary Search.