(psychoanalysis) the governing principle of the id; the principle that an infant seeks gratification and fails to distinguish fantasy from reality | a basic truth or law or assumption |
| a rule or standard especially of good behavior |
| (law) an explanation of the fundamental reasons (especially an explanation of the working of some device in terms of laws of nature) |
| a basic generalization that is accepted as true and that can be used as a basis for reasoning or conduct |
| a rule or law concerning a natural phenomenon or the function of a complex system |
| rule of personal conduct |