critical angle

1. 1.

   the smallest angle of incidence for which light is totally reflected

   Broaderangle of incidence

Questions about critical angle

What does critical angle mean?

critical angle means "the smallest angle of incidence for which light is totally reflected".

Is critical angle a common word?

critical angle is banded "Rare" — specialist or archaic — most readers will not have met it. The band comes from how often the word appears in a large corpus of everyday English, not from an editor's impression.