- Date: 14th century
- b (1) : a rule or code of conduct (2) : habitual devotion to right principles <a man of principle>
- c : the laws or facts of nature underlying the working of an artificial device
- 2 : a primary source : origin
- 3 a : an underlying faculty or endowment <such principles of human nature as greed and curiosity>
- 4 capitalized Christian Science : a divine principle : god
— in principle : with respect to fundamentals <prepared to accept the proposition in principle> usage Although nearly every handbook and many dictionaries warn against confusing principle and principal, many people still do. Principle is only a noun; principal is both adjective and noun.