narrowness has 3 distinct synonyms spread across 2 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 wideness.
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.
an inclination to criticize opposing opinions or shocking behavior
Synonyms, antonyms and the broader and narrower relations for narrowness come from Princeton University’s WordNet. Full sources and licences.
a restriction of range or scope
“the problem with achievement tests is the narrowness they impose on students”
a small margin
“the president was not humbled by his narrow margin of victory”