minder has 2 distinct synonyms spread across 1 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.
someone (usually in totalitarian countries) who is assigned to watch over foreign visitors
“I turned around and there, a few hundred feet away, was our government minder, Li Wong Su, huffing and puffing toward us”
a person who looks after babies (usually in the person's own home) while the babys' parents are working
Synonyms, antonyms and the broader and narrower relations for minder come from Princeton University’s WordNet. Full sources and licences.