inward has 3 distinct synonyms spread across 3 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 outward.
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.
relating to or existing in the mind or thoughts
“a concern with inward reflections”
toward the center or interior
“move the needle further inwards!”
Synonyms, antonyms and the broader and narrower relations for inward come from Princeton University’s WordNet. Full sources and licences.