deflationary spiral has no recorded synonym. Each sense below keeps its own list, because a synonym belongs to a meaning and not to a word: swapping one sense's substitute into another sense's sentence is how a thesaurus makes writing worse. Its one recorded opposite is inflationary spiral.
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.
an episode of deflation in which prices and wages decrease at an increasing rate and currency gains in value
Synonyms, antonyms and the broader and narrower relations for deflationary spiral come from Princeton University’s WordNet. Full sources and licences.