Recursion
Re•cur•sion
[rikurzhuh n]
Noun

Mathematics:
The determination of a succession of elements
(such as numbers or functions) by operation on
one or more preceding elements according to a
rule or formula involving a finite number of
steps.

Computers:
A computer programming technique involving the
use of a procedure, subroutine, function, or
algorithm that calls itself one or more times
until a specified condition is met at which
time the rest of each repetition is processed
from the last one called to the first.
Etymology
From Late Latin recursion, recursio, from
recurrere
First known use: 1790