# A set of statements or principles devised to explain a group of facts or phenomena, especially one that has been repeatedly tested or is widely accepted and can be used to make predictions about natural phenomena.
or Maybe you prefer:
# An assumption based on limited information or knowledge; a conjecture.
A systematically organized body of knowledge applicable in a relatively wide variety of circumstances, especially a system of assumptions, accepted principles, and rules of procedure devised to analyze, predict, or otherwise explain the nature or behavior of a specified set of phenomena.
dictionary.reference.com...
[edit on 2-5-2005 by dreamlandmafia]

