'Critical angle' definitions:

Definition of 'critical angle'

From: WordNet
noun
The smallest angle of incidence for which light is totally reflected

Definition of 'Critical angle'

From: GCIDE
  • Critical \Crit"ic*al\ (kr[i^]t"[i^]*kal), a. [See Critic, n., Crisis.] [1913 Webster]
  • 1. Qualified to criticise, or pass judgment upon, literary or artistic productions. [1913 Webster]
  • It is submitted to the judgment of more critical ears to direct and determine what is graceful and what is not. --Holder. [1913 Webster]
  • 2. Pertaining to criticism or the critic's art; of the nature of a criticism; accurate; as, critical knowledge; a critical dissertation. [1913 Webster]
  • 3. Inclined to make nice distinctions, or to exercise careful judgment and selection; exact; nicely judicious. [1913 Webster]
  • Virgil was so critical in the rites of religion, that he would never have brought in such prayers as these, if they had not been agreeable to the Roman customs. --Bp. Stillingfleet. [1913 Webster]
  • 4. Inclined to criticise or find fault; fastidious; captious; censorious; exacting. [1913 Webster]
  • O gentle lady, do not put me to 't, For I am nothing, if not critical. --Shak. [1913 Webster]
  • 5. Characterized by thoroughness and a reference to principles, as becomes a critic; as, a critical analysis of a subject. [1913 Webster]
  • 6. [See Crisis.] Pertaining to, or indicating, a crisis, turning point, or specially important juncture; important as regards consequences; hence, of doubtful issue; attended with risk; dangerous; as, the critical stage of a fever; a critical situation. [1913 Webster]
  • Our circumstances are indeed critical. --Burke. [1913 Webster]
  • The small moment, the exact point, the critical minute, on which every good work so much depends. --South. [1913 Webster]
  • Critical angle (Optics), that angle of incidence of a luminous ray at which it is wholly reflected, and no portion of it transmitted. The sine of this angle is the reciprocal of the refractive index of the medium.
  • Critical philosophy, the metaphysical system of Kant; -- so called from his most important work, the "Critique of Pure Reason." [1913 Webster]