brush has 10 distinct synonyms spread across 6 of its 15 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 dense growth of bushes
an implement that has hairs or bristles firmly set into a handle
conducts current between rotating and stationary parts of a generator or motor
a bushy tail or part of a bushy tail (especially of the fox)
the act of brushing your teeth
“the dentist recommended two brushes a day”
contact with something dangerous or undesirable
“I had a brush with danger on my way to work”
Synonyms, antonyms and the broader and narrower relations for brush come from Princeton University’s WordNet. Full sources and licences.
clean with a brush
“She brushed the suit before hanging it back into the closet”
remove with or as if with a brush
“brush away the crumbs”
cover by brushing
“brush the bread with melted butter”