office has 18 distinct synonyms spread across 6 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.
place of business where professional or clerical duties are performed
“he rented an office in the new building”
an administrative unit of government
“the Central Intelligence Agency”
(of a government or government official) holding an office means being in power
“being in office already gives a candidate a great advantage”
professional or clerical workers in an office
“the whole office was late the morning of the blizzard”
a religious rite or service prescribed by ecclesiastical authorities
“the offices of the mass”
a job in an organization
“he occupied a post in the treasury”
Synonyms, antonyms and the broader and narrower relations for office come from Princeton University’s WordNet. Full sources and licences.