infect has 1 distinct synonym spread across 1 of its 4 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 disinfect.
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.
Synonyms, antonyms and the broader and narrower relations for infect come from Princeton University’s WordNet. Full sources and licences.
corrupt with ideas or an ideology
“society was infected by racism”
affect in a contagious way
“His laughter infects everyone who is in the same room”