(algebra) An operation taking two operands.

(algebra, computing) A symbol representing unary operation; an operator taking one operand.

(set theory) A mathematical operation that returns a set taking one or more sets as input.

(algebra) An operation taking one operand, such as the square, factorial or absolute value operation.

(algebra, computing) A symbol representing binary operation; an operator taking two operands.

(law) An application of a legal rule that automatically brings about a legal consequence.

Alternative spelling of postoperative

Alternative spelling of cooperation

A description, usually graphical, showing the major participants or components in a system and their interrelationships.

(business) A corporate officer of a corporation, company, or agency, responsible for executing decisions of the chief executive officer (CEO) according to their decided schedule; often initialised as COO.