visibility has 2 distinct synonyms spread across 2 of its 3 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 invisibility.
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.
quality or fact or degree of being visible; perceptible by the eye or obvious to the eye
“low visibility caused by fog”
degree of exposure to public notice
“that candidate does not have sufficient visibility to win an election”
capability of providing a clear unobstructed view
“a windshield with good visibility”
Synonyms, antonyms and the broader and narrower relations for visibility come from Princeton University’s WordNet. Full sources and licences.