Definition of angular defect in English:

angular defect

noun

Mathematics
  • 1(In non-Euclidean geometry) the difference between the sum of the interior angles of a given figure and that of the same figure as it would appear in the Euclidean plane.

  • 2The difference between the sum of the angles at any vertex of a regular polyhedron and 360°.

Origin

Mid 19th century; earliest use found in Edinburgh New Philosophical Journal.