A small contrasting part of something. Synonyms:dapple, fleck, patch, speckle, spot."A leopard's spots" , "A patch of clouds" , "Patches of thin ice" , "A fleck of red"
2.
The act of spotting or staining something. Synonyms:spotting, staining.
... that solar maculation depends in some way upon the position of the planets occurred to Galileo in 1612.[493] It has been industriously sifted by a whole bevy of modern solar physicists. Wolf in 1859[494] found reason to believe that the eleven-year curve is determined by the action of Jupiter, ... — A Popular History of Astronomy During the Nineteenth Century - Fourth Edition • Agnes M. (Agnes Mary) Clerke