Definition of limiting angle in English:

limiting angle

See synonyms for limiting angle

noun

Optics
  • The largest angle of incidence (between the ray and the perpendicular to the surface) for which a ray will pass from a dense medium into a less dense one.

    An incident ray striking at a larger angle (i.e. a more glancing ray) is reflected, and does not enter the other medium.

Origin

Late 18th century; earliest use found in Philosophical Transactions of the Royal Society of London.