pattern, n
1. 'The original proposed to imitation; the archetype; that
which is to be copied; an exemplar' (J.); an example or model
deserving imitation; an example or model of a particular excellence.
2. Anything fashioned, shaped, or designed to serve as a model
from which something is to be made; a model, design, plan, or
outline.
-- Oxford English Dictionary, 2nd edn
The elements of this language are elements called patterns.
Each pattern describes a problem which occurs over and over again in
our environment, and then describes the core of the solution to that
problem, in such a way that you can use this solution a million
times over, without ever doing it the same way twice.
Alexander
et al. A Pattern Languge, p x. 1977
A pattern is a particular arrangement of elements that
constitute a model to be used or emulated. Patterns are patterns if
they can do something, if they can cause something to occur with
some regularity. ... a pattern [is] an arrangement that expresses a
reproducible and meaningful relationship between relatively
independent components.
Cohen.
Tending Adam's Garden, §131. 2000