WordNet records no synonym and no antonym for cross section. 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.
a sample meant to be representative of a whole population
Synonyms, antonyms and the broader and narrower relations for cross section come from Princeton University’s WordNet. Full sources and licences.
(physics) the probability that a particular interaction (as capture or ionization) will take place between particles; measured in barns