WordNet records no synonym and no antonym for hittite. 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 member of an ancient people who inhabited Anatolia and northern Syria about 2000 to 1200 BC
the language of the Hittites and the principal language of the Anatolian group of languages; deciphered from cuneiform inscriptions
1 of the 3 recorded senses carries no synonym, antonym or related term, so it is not shown above. Every sense, with its definition and examples, is on the full entry for hittite.
Synonyms, antonyms and the broader and narrower relations for hittite come from Princeton University’s WordNet. Full sources and licences.