Definition of principle
1a
: 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
b
: an ingredient (such as a chemical) that exhibits or imparts a characteristic quality
in principle
: with respect to fundamentals
prepared to accept the proposition in principle
Keep scrolling for more
Keep scrolling for more
Keep scrolling for more
Keep scrolling for more
Test Your Vocabulary
Who Knew?
-
- What is a ruelle?

Can you spell these 10 commonly misspelled words?
TAKE THE QUIZ
A daily challenge for crossword fanatics.
TAKE THE QUIZLove words? Need even more definitions?
Merriam-Webster unabridged
Words at Play
Ask the Editors
Word Games
Share principle
Time Traveler for principle
The first known use of principle was in the 14th century
See more words from the same century