WordNet sense 1 (a fat-soluble vitamin that prevents rickets):

calciferol, ergocalciferol, viosterol, vitamin D, cholecarciferol

WordNet sense 2 (the cardinal number that is the product of one hundred and five):

five hundred

WordNet sense 3 (the 4th letter of the Roman alphabet):

letter d

WordNet sense 4 (being or denoting a numerical quantity but not order):

cardinal