WordNet records no synonym and no antonym for yips. 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.
nervous tension that causes an athlete to fail (especially causes golfers to miss short putts)
“to avoid the yips he changed his style of putting”
Synonyms, antonyms and the broader and narrower relations for yips come from Princeton University’s WordNet. Full sources and licences.