A pattern, from the French patron, is a theme of reoccurring events or objects, sometimes referred to as elements of a set. These elements repeat in a predictable manner.
http://en.wikipedia.org/wiki/Pattern

Sewing Patterns and clothing patterns from SewingPatterns.com including clothing patterns and dress patterns from simplicity patterns.
http://www.sewingpatterns.com/

In software engineering, a design pattern is a general reusable solution to a commonly occurring problem in software design. A design pattern is not a finished design that can be ...
http://en.wikipedia.org/wiki/Design_pattern_%28computer_scie ...

The Hillside Group is a nonprofit corporation dedicated to improving human communication about computers by encouraging people to codify common programming and design practice.
http://hillside.net/patterns/

A wiki with principles, gotchas, frameworks, and common techniques. Also the homepage for the "Ajax Design Patterns" book.
http://ajaxpatterns.org/