principles
n. countablen. the basic rules or beliefs that guide how you behave or how something works. They are the core ideas that help you decide what is right or wrong.
n. fundamental truths, laws, or beliefs that serve as the foundation for a system of thought or behavior. Often refers to a personal code of conduct or the underlying physical laws of a science.
She refuses to lie because it goes against her principles.
The architect designed the building based on the principles of sustainable energy and natural light.
While the two political parties agree on the desired outcome, they differ fundamentally on the economic principles required to achieve long-term stability for the working class.
Usually used in the plural when referring to a person's moral code or the basic laws of a discipline.
the main principals of biologythe main principles of biologyLearners often confuse 'principles' (rules/laws) with 'principals' (heads of schools or main participants).