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 four.

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”.

• quadrate
• quadrature

• square

• quadratic in Webster’s Revised Unabridged Dictionary, G. & C. Merriam, 1913.
• quadratic in The Century Dictionary, New York, N.Y.: The Century Co., 1911.
• quadratic at OneLook Dictionary Search