WordNet records no synonym and no antonym for colossus of rhodes. It is the only member of its synset, 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 huge bronze statue of the sun god Helios that was built around 285 BC and that stood beside the harbor entrance on the island of Rhodes for about 50 years before it was toppled by an earthquake
Synonyms, antonyms and the broader and narrower relations for colossus of rhodes come from Princeton University’s WordNet. Full sources and licences.