principle/ˈprɪnsəpl/
▶noun - 2 a general scientific theorem or natural law.
- 4 Chemistry an active or characteristic constituent of a substance.
– phrases
in principle in theory.
on principle because of one's adherence to a particular belief.
– origin ME: from OFr., from L. principium ‘source’, principia (pl.) ‘foundations’, from princeps, princip- ‘first, chief’.
usage: Note that principle and principal do not have the same meaning. Principle is normally used as a noun meaning ‘a fundamental basis of a system of thought or belief’, as in this is one of the basic principles of democracy. Principal, on the other hand, is normally an adjective meaning ‘main or most important’, as in one of the country's principal cities. As a noun principal refers to the most senior or most important person in an organization: the deputy principal.