des has 6 distinct synonyms spread across 2 of its 2 senses. Each sense below keeps its own list, because a synonym belongs to a meaning and not to a word: swapping one sense's substitute into another sense's sentence is how a thesaurus makes writing worse. WordNet records no antonym for it — antonymy is a relation between word forms rather than concepts, so it is deliberately sparse.
Counts are distinct word forms across every sense. A synonym that appears under three senses is counted once here and shown three times below, under each sense it belongs to.
a potent estrogen used in medicine and in feed for livestock and poultry
synthetic nonsteroid with the properties of estrogen; formerly used to treat menstrual problems but was found to be associated with vaginal cancers in the daughters of women so treated during pregnancy
Synonyms, antonyms and the broader and narrower relations for des come from Princeton University’s WordNet. Full sources and licences.