Euphemism is a word or expression used to soften or avoid direct references to taboo or offensive topics while maintaining politeness. Euphemisms are used to soften expressions by making unpolite truths sound less harsh, such as using "passed on" instead of "died." They also show politeness by avoiding places one might not want to say in polite company, like using "big-boned" instead of "heavy." Less pleasant euphemisms can show impoliteness, like using "blow chunks" instead of "vomited." The document provides examples of euphemisms used for different purposes and ends with acknowledgements.