From WordNet (r) 3.0 (2006):
d adj 1: denoting a quantity consisting of 500 items or units [syn: five hundred, 500, d] n 1: a fat-soluble vitamin that prevents rickets [syn: vitamin D, calciferol, viosterol, ergocalciferol, cholecalciferol, D] 2: the cardinal number that is the product of one hundred and five [syn: five hundred, 500, D] 3: the 4th letter of the Roman alphabet [syn: D, d]