WordNet records no synonym and no antonym for keyboard. 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.
device consisting of a set of keys on a piano or organ or typewriter or typesetting machine or computer or the like
holder consisting of an arrangement of hooks on which keys or locks can be hung
Synonyms, antonyms and the broader and narrower relations for keyboard come from Princeton University’s WordNet. Full sources and licences.