blur has 12 distinct synonyms spread across 6 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 focus.
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.
become glassy; lose clear vision
“Her eyes glazed over from lack of sleep”
make unclear, indistinct, or blurred
“Her remarks confused the debate”
become vague or indistinct
“The distinction between the two theories blurred”
a hazy or indistinct representation
“it happened so fast it was just a blur”
Synonyms, antonyms and the broader and narrower relations for blur come from Princeton University’s WordNet. Full sources and licences.