1 antonym for improved: unimproved. Fast is an antonym of slow. See more. Synonyms for improvement in Free Thesaurus. Find another word for enhance. Synonyms-thesaurus.com is more than 70,800 synonyms and 47,200 antonyms available. 26 synonyms of enhance from the Merriam-Webster Thesaurus, plus 58 related words, definitions, and antonyms. Antonyms for improve include impair, deteriorate, ruin, diminish, disimprove, decrease, hinder, recede, reduce and lessen. Synonyms for improved in Free Thesaurus. What is the opposite of Improve? Find more ways to say improved, along with related words, antonyms and example phrases at Thesaurus.com, the world's most trusted free thesaurus. Antonym definition, a word opposite in meaning to another. 34 synonyms of developed from the Merriam-Webster Thesaurus, plus 118 related words, definitions, and antonyms. Another word for better. Improvement: an instance of notable progress in the development of knowledge, technology, or skill. Synonyms for improve in Free Thesaurus. 5 synonyms of improvement from the Merriam-Webster Thesaurus, plus 34 related words, definitions, and antonyms. Antonyms for improve. Antonyms for improvement. Find more ways to say better, along with related words, antonyms and example phrases at Thesaurus.com, the world's most trusted free thesaurus. Here you use the antonyms for improve. Find another word for improvement. Antonyms for Improve (opposite of Improve). Find more opposite words at wordhippo.com! Antonyms for improved. These antonyms of the word improve are provided for information only. What are synonyms for improved? Another word for improved. Find another word for developed.