(mathematics) Any metric space whose elements are functions

(systems theory) That part of a control system that dynamically updates the parameters of an optimizing control function or a direct control function

(medicine) A branch of kinesiology that studies the configuration of limbs during the performance of a task.

(mathematics) Any function in which the interchange of two independent variables changes the sign of the dependent variable.

(mathematics) An inverse hyperbolic function

(mathematics) An inverse hyperbolic function

(algebraic geometry) Informally, any function expressible using (only) the operations of addition, subtraction, multiplication, division and raising to a rational power; more precisely, any continuous function definable as the root of some polynomial equation.

(mathematics) an inverse trigonometric function

(idiomatic) Irregular, often illegal, activities.

(mathematics) Any function whose value is zero except for a finite part of its argument for which it has a constant non-zero value