quad ‧ rat ‧ ic e ‧ qua ‧ tion /kwɒˌdrætɪk ɪˈkweɪʒ ə n $ kwɑː-/ BrE AmE noun [countable]
[ Date: 1600-1700 ; Origin: quadratic from quadrate 'square' (14-21 centuries) , from Latin quadratus , past participle of quadrare 'to make square' ]
technical an ↑ equation such ax²+by+c = z, which includes numbers or quantities multiplied by themselves