regulation has 5 distinct synonyms spread across 4 of its 7 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.
the state of being controlled or governed
(embryology) the ability of an early embryo to continue normal development after its structure has been somehow damaged or altered
the act of bringing to uniformity; making regular
the act of controlling or directing according to rule
“fiscal regulations are in the hands of politicians”
1 of the 7 recorded senses carries no synonym, antonym or related term, so it is not shown above. Every sense, with its definition and examples, is on the full entry for regulation.
Synonyms, antonyms and the broader and narrower relations for regulation come from Princeton University’s WordNet. Full sources and licences.