Quantcast
Merriam-Webster Logo
  • Dictionary
  • Thesaurus
  • Medical
  • Scrabble
  • Spanish Central
  • Learner's Dictionary

critical angle

noun

Definition of critical angle

  1. :  the least angle of incidence at which total reflection takes place



Illustration of critical angle

1873

First Known Use of critical angle

1873


Learn More about critical angle


Seen and Heard

What made you want to look up critical angle? Please tell us where you read or heard it (including the quote, if possible).

WORD OF THE DAY

February 13, 2016

a trying or distressing experience

Get Word of the Day daily email!

WORD GAMES

Take a 3-minute break and test your skills!

image33683556

How much does a batman (the Turkish unit of measurement) weigh?

16.96 pounds 100 pounds 196.5 pounds 2.2 pounds
Name That Thing

10 quick questions: hear them, spell them, and see how your skills compare to the crowd.

TAKE THE QUIZ
SCRABBLE® Sprint

Test Your Knowledge - and learn some interesting things along the way.

TAKE THE QUIZ