east has 5 distinct synonyms spread across 3 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. Its one recorded opposite is west.
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 cardinal compass point that is at 90 degrees
the region of the United States lying to the north of the Ohio River and to the east of the Mississippi River
the direction corresponding to the eastward cardinal compass point
a location in the eastern part of a country, region, or city
situated in or facing or moving toward the east
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 east.
Synonyms, antonyms and the broader and narrower relations for east come from Princeton University’s WordNet. Full sources and licences.