### adjective

1Mathematics Geometry

Designating a triangle in which, with respect to a given conic section, each side lies on the polar of the vertex to which it is opposite. Also: designating a point which intersects its own polar, or a line which intersects its own pole.2Mathematics

Of a function: †(a) (in the mathematics of quaternions) a function f for which the scalar part of x ⋅ f (y) is the same as that of y ⋅ f (x), regardless of the choice of x and y (obsolete); (b) (in a Boolean algebra) a function f for which f (x)⋅ y = 0 if and only if f (y)⋅ x = 0 (now rare).3Mathematics

Designating a partition in which each row of its Young or Ferrers diagram has the same number of boxes or dots as the corresponding column.4Mathematics

rare Designating a matrix that is the transpose of itself; (in later use also) designating a matrix that is identical to the matrix formed from its transpose by taking the complex conjugate of each entry; = "Hermitian".5Mathematics

Designating a subgroup that contains every element of the form ghg −1, where h is any element of the subgroup and g any element of the group in which it lies.

**Origin**

Mid 19th century; earliest use found in George Salmon (1819–1904), mathematician and theologian. From self- + conjugate.