WordNet records no synonym and no antonym for half binding. 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.
book binding in which the spine and part of the sides are bound in one material and the rest in another
Synonyms, antonyms and the broader and narrower relations for half binding come from Princeton University’s WordNet. Full sources and licences.