adjective

• drawing upon itself, referring back.
• (mathematics, not comparable) of an expression, each term of which is determined by applying a formula to preceding terms
• (computing, not comparable) of a program or function that calls itself
• (computing theory, not comparable, of a function) which can be computed by a theoretical model of a computer, in a finite amount of time
• (computing theory, not comparable, of a set) whose characteristic function is recursive (4)