When it comes to thinning out a solution or mixture, the term thinners can often be used. However, if you're looking for alternative synonyms, there are a range of words that can be interchangeable with thinners. Some of the most common synonyms for thinners include diluents, solvents, reducers, thickeners and extenders. Depending on the context in which the word is used, some of these alternatives may be more appropriate than others. For instance, reducers may be more applicable when discussing paint and coatings, while extenders may be used more when discussing adhesives or other materials. Ultimately, choosing the right synonym for thinners will help you to discuss your needs and goals more accurately.