mi has 21 distinct synonyms spread across 7 of its 8 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.
destruction of heart tissue resulting from obstruction of the blood supply to the heart muscle
a former British unit of length equivalent to 6,080 feet (1,853.184 meters); 800 feet longer than a statute mile
a unit of length used in navigation; exactly 1,852 meters; historically based on the distance spanned by one minute of arc in latitude
a unit of length equal to 1,760 yards or 5,280 feet; exactly 1609.344 meters
a midwestern state in north central United States in the Great Lakes region
the government agency in the United Kingdom that is responsible for internal security and counterintelligence on British territory
the government agency in the United Kingdom that is responsible for internal security and counterintelligence overseas
the syllable naming the third (mediant) note of any major scale in solmization
Synonyms, antonyms and the broader and narrower relations for mi come from Princeton University’s WordNet. Full sources and licences.