Main Entry: prin·ci·ple

Pronunciation: \ˈprin(t)-s(ə-)pəl, -sə-bəl\

Function: noun

Etymology: Middle English, from Middle French principe, principle, from Old French, from Latin principium beginning, from princip-, princeps initiator — more at prince

Date: 14th century

1 a : a comprehensive and fundamental law, doctrine, or assumption 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> b : an ingredient (as a chemical) that exhibits or imparts a characteristic quality
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. If you are unsure which noun you want, read the definitions in this dictionary.