1. [noun] A fundamental assumption or guiding belief.
2. [noun] A rule used to choose among solutions to a problem.
3. [noun] (sometimes pluralized) Moral rule or aspect.
4. [noun] (physics) A rule or law of nature, or the basic idea on how the laws of nature are applied.
5. [noun] A fundamental essence, particularly one producing a given quality.
6. [noun] (obsolete) A beginning.
7. [noun] A source, or origin; that from which anything proceeds; fundamental substance or energy; primordial substance; ultimate element, or cause.
8. [noun] An original faculty or endowment.
9. [verb] (transitive) To equip with principles; to establish, or fix, in certain principles; to impress with any tenet or rule of conduct.
10. [noun] A basic generalization that is accepted as true and that can be used as a basis for reasoning or conduct; 'their principles of composition characterized all their works'.
11. [noun] A rule or standard especially of good behavior; 'a man of principle'; 'he will not violate his principles'.
12. [noun] A basic truth or law or assumption; 'the principles of democracy'.
13. [noun] A rule or law concerning a natural phenomenon or the function of a complex system; 'the principle of the conservation of mass'; 'the principle of jet propulsion'; 'the right-hand rule for inductive fields'.
14. [noun] Rule of personal conduct.
15. [noun] (law) an explanation of the fundamental reasons (especially an explanation of the working of some device in terms of laws of nature); 'the rationale for capital punishment'; 'the principles of internal-combustion engines'.
