Definition of Riemann integral in English:

Riemann integral

(also Riemann's integral)

noun

Mathematics
  • A definite integral calculated by dividing an area under a curve of a real function into a number of rectangular intervals of equal width, summing the areas of these rectangles, and then taking the limit of the sum as the width of the intervals tends to zero.

Origin

Late 19th century; earliest use found in Mathematische Annalen.