A euphemism is a word or phrase used to mask a rude or offensive concept. These figures of speech provide a technique to avoid taboos by being polite. Many euphemisms are so common, that we don't even recognize them as such. Perhaps the best way to learn about euphemisms is to investigate some clever examples:

• We are experiencing heavy casualties (many soldiers are being killed)
• There is a logjam in the river (constipation)
• Downsizing, rightsizing or laying off (getting rid of employees)
• Praying to the porcelain altar (vomiting into the toilet)
• If something happens to me (if i die)
• Sanitation Worker (trash collector)
• Unplanned landing (plane crash)
• Mal de mer (seasickness)

They usually fall into one of the following categories:

• Abbreviations: B.O. (body odor), W.C. (toilet)
• Foreign words: faux (fake), or faux pas (foolish error)
• Abstractions: before i go (before i die)
• Indirections: rear-end, unmentionables
• Longer words: flatulence, perspiration, mentally challenged
• Technical terms: gluteus maximus
• Mispronunciation: darn, shoot

Cacophemism or dysphemism are the opposites of euphemism. A dysphemism is an offensive substitute of something inoffensive. Let us consider a lazy person who is watching television, for example; he may euphemize his behavior by saying that he is 'recuperating from work'. A correlated dysphemism, or insulting substitute would be 'couch potato'.