situation has 9 distinct synonyms spread across 4 of its 5 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 general state of things; the combination of circumstances at a given time
“the present international situation is dangerous”
a complex or critical or unusual difficulty
“the dangerous situation developed suddenly”
physical position in relation to the surroundings
“the sites are determined by highly specific sequences of nucleotides”
a job in an organization
“he occupied a post in the treasury”
Synonyms, antonyms and the broader and narrower relations for situation come from Princeton University’s WordNet. Full sources and licences.