(obsolete) The act of spotting; a spot; a blemish.
1891, Ambrose Bierce, “A Holy Terror” in Tales of Soldiers and Civilians, San Francisco: E. L. G. Steele, p. 218,
He could make out a mottled pattern on the hollow cheeks—the maculations of decay.
(zoology, botany, chiefly uncountable) A pattern of spots.
1990, Mason E. Hale, A Synopsis of the Lichen Genus Xanthoparmelia (Vainio) Hale (Ascomycotina, Parmeliaceae), Washington, DC: Smithsonian Institution Press, p. 195,
[This lichen] species […] is recognized by […] more or less distinct maculation on the upper surface, and pale brown lower surface.