The antonyms for the word "under-estimates" are "over-estimates," "overrate," "overrate," "exaggerate," and "inflate." To over-estimate means to estimate too high, while to under-estimate means to estimate too low. Therefore, over-estimates are opposite in meaning to under-estimates, which refers to an estimate or assessment that is too low. Overrating means to value too highly while inflating means to exaggerate or increase something beyond its actual size or value. In essence, antonyms form pairs or sets of words with opposite meanings to another word. By examining and practicing the application of antonyms, individuals can accurately articulate their ideas and communicate more effectively.