quadric
noun [ C ] mathematics specialized uk/ˈkwɒd.rɪk/ us/ˈkwɑː.drɪk/
二次曲面;二次曲线
a curve or surface that is described by an equation (= a mathematical statement in which you show that two amounts are equal) that has at least one variable (= a number that can change) that is squared (= multiplied by itself)