WordNet records no synonym and no antonym for recombination. It is the only member of each of its synsets, which is common for technical, taxonomic and single-sense vocabulary — there is no other English word that means the same thing. The broader and narrower terms below are the useful relations in that case.
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.
(physics) a combining of charges or transfer of electrons in a gas that results in the neutralization of ions; important for ions arising from the passage of high-energy particles
(genetics) a combining of genes or characters different from what they were in the parents
Synonyms, antonyms and the broader and narrower relations for recombination come from Princeton University’s WordNet. Full sources and licences.