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, involving the second power (square) of a variable but no higher powers, as ${\displaystyle ax^{2}+bx+c}$.
3. (mathematics) Of an equation, of the form ${\displaystyle ax^{2}+bx+c=0}$.
4. (mathematics) Of a function, of the form ${\displaystyle y=ax^{2}+bx+c}$.

quadratic (plural quadratics)

1. (mathematics) A quadratic polynomial, function or equation.

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.
• “quadratic”, in The Century Dictionary […], New York, N.Y.: The Century Co., 1911, →OCLC.
• “quadratic”, in OneLook Dictionary Search.