Abstract art is art that does not depict objects in the natural world, but instead uses colour and form in a non-representational way. In the very early 20th century, the term was ...
http://en.wikipedia.org/wiki/Abstract_art

Abstract may refer to: Abstract (law) Abstract (summary) Abstract art; Abstract object See also. Abstraction (disambiguation)
http://en.wikipedia.org/wiki/Abstract

adjective . 1. thought of apart from concrete realities, specific objects, or actual instances: an abstract idea.
http://dictionary.reference.com/search?q=abstract

How to Write an Abstract. Philip Koopman, Carnegie Mellon University October, 1997. Abstract. Because on-line search databases typically contain only abstracts, it is vital to ...
http://www.ece.cmu.edu/~koopman/essays/abstract.html

The abstract modifier can be used with classes, methods, properties, indexers, and events. Use the abstract modifier in a class declaration to indicate that a class is intended ...
http://msdn.microsoft.com/en-us/library/sf985hc5(VS.80).aspx