principle

The definition of a principle is a basic truth or the source or origin of something or someone.

(noun)

An example of principle is a list of values set by a group of people.

See principle in Webster's New World College Dictionary

noun

the ultimate source, origin, or cause of something
a natural or original tendency, faculty, or endowment
a fundamental truth, law, doctrine, or motivating force, upon which others are based: moral principles
1. a rule of conduct, esp. of right conduct
2. such rules collectively
3. adherence to them; integrity; uprightness: a man of principle
an essential element, constituent, or quality, esp. one that produces a specific effect: the active principle of a medicine
1. the scientific law that explains a natural action: the principle of cell division
2. the method of a thing's operation: the principle of a gasoline engine is internal combustion

Origin: ME, altered < MFr principe < L principium: see principium

See principle in American Heritage Dictionary 4

noun

A basic truth, law, or assumption: the principles of democracy.
a. A rule or standard, especially of good behavior: a man of principle.
b. The collectivity of moral or ethical standards or judgments: a decision based on principle rather than expediency.
A fixed or predetermined policy or mode of action.
A basic or essential quality or element determining intrinsic nature or characteristic behavior: the principle of self-preservation.
A rule or law concerning the functioning of natural phenomena or mechanical processes: the principle of jet propulsion.
Chemistry One of the elements that compose a substance, especially one that gives some special quality or effect.
A basic source. See Usage Note at principal.