approachable 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 unapproachable.
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.
capable of being read with comprehension
“readily accessible to the nonprofessional reader”
easy to meet or converse or do business with
“a friendly approachable person”
Synonyms, antonyms and the broader and narrower relations for approachable come from Princeton University’s WordNet. Full sources and licences.