concentrated has 2 distinct synonyms spread across 2 of its 5 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 distributed.
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.
gathered together or made less diffuse
“their concentrated efforts”
(of light) transmitted directly from a pointed light source
being the most concentrated solution possible at a given temperature; unable to dissolve still more of a substance
“a saturated solution”
2 of the 5 recorded senses carry no synonym, antonym or related term, so they are not shown above. Every sense, with its definition and examples, is on the full entry for concentrated.
Synonyms, antonyms and the broader and narrower relations for concentrated come from Princeton University’s WordNet. Full sources and licences.