WordNet sense 1 (a cooler darker spot appearing periodically on the sun's photosphere; associated with a strong magnetic field):

sunspot

WordNet sense 2 (a yellowish central area of the retina that is rich in cones and that mediates clear detailed vision):

yellow spot, macula lutea, macular area

WordNet sense 3 (a patch of skin that is discolored but not usually elevated; caused by various diseases):

macule