law of contradiction
Definition of law of contradiction
: a principle in logic: a thing cannot at the same time both be and not be of a specified kind (as a table and not a table) or in a specified manner (as red or not red)
Test Your Vocabulary
Slippery Words Quiz—Changing with the Times
- What is an earlier meaning of nice?

Test your knowledge - and maybe learn something along the way.
TAKE THE QUIZ
Anagram puzzles meet word search.
TAKE THE QUIZLove words? Need even more definitions?
Merriam-Webster unabridgedWords at Play
Ask the Editors
Word Games
Slippery Words Quiz—Changing with the Times
Do you know these earlier meanings of words?
Take the quizWords of Snow and Ice Quiz
A selection of words from the chillier parts of t...
Take the quizTrue or False?
Test your knowledge - and maybe learn something a...
Take the quizSCRABBLE® Sprint
SCRABBLE® fans, sharpen your skills!
Play the game
Share law of contradiction