WordNet records no synonym and no antonym for newsroom. 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.
the staff of a newspaper or the news department of a periodical
“every newspaper editor is criticized by the newsroom”
an office in which news is processed by a newspaper or news agency or television or radio station
a reading room (in a library or club) where newspapers and other periodicals can be read
Synonyms, antonyms and the broader and narrower relations for newsroom come from Princeton University’s WordNet. Full sources and licences.