replication has 11 distinct synonyms spread across 4 of its 7 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.
the act of making copies
“Gutenberg's reproduction of holy texts was far more efficient”
(genetics) the process whereby DNA makes a copy of itself before cell division
(law) a pleading made by a plaintiff in reply to the defendant's plea or answer
the repetition of a sound resulting from reflection of the sound waves
“she could hear echoes of her own footsteps”
copy that is not the original; something that has been copied
the repetition of an experiment in order to test the validity of its conclusion
“scientists will not believe an experimental result until they have seen at least one replication”
Synonyms, antonyms and the broader and narrower relations for replication come from Princeton University’s WordNet. Full sources and licences.