Synonyms for caustic Found 13 synonyms across 2 meanings for “caustic”. harsh or corrosive in tone (adj) acerbacerbicacidacridbitterblisteringsulfuroussulphurousvirulentvitriolic of a substance, especially a strong acid (adj) corrosiveerosivemordant Explore Related Words Rhymes with causticSynonyms for acerbSynonyms for acerbicSynonyms for acidSynonyms for acridSynonyms for bitter Synonym Finder | Rhyme Finder | Poetry Editor