agglutination has 1 distinct synonym spread across 1 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. WordNet records no antonym for it — antonymy is a relation between word forms rather than concepts, so it is deliberately sparse.
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.
a clumping of bacteria or red cells when held together by antibodies (agglutinins)
the building of words from component morphemes that retain their form and meaning in the process of combining
the coalescing of small particles that are suspended in solution; these larger masses are then (usually) precipitated
Synonyms, antonyms and the broader and narrower relations for agglutination come from Princeton University’s WordNet. Full sources and licences.