There are words in every language which people instinctively avoid because they are considered indecent, indelicate, rude, too direct or impolite. As the "offensive" referents, for which these words stand, must still be alluded to, they are often described in a round-about
way, by using substitutes called euphemisms. This device is dictated by social conventions which are sometimes apt to be over-sensitive, see "indecency" where there is none and seek refinement in absurd avoidances and pretentiousness.
The word lavatory has, naturally, produced many euphemisms. Here are some of them: powder room, washroom, restroom, retiring room, (public) comfort station, ladies' (room), gentlemen's (room), water-closet, w.c. ([d0blju:'si:]), public conveniences and even Windsor castle (which is a comical phrase for "deciphering" w.c.).
Pregnancy is another topic for "delicate" references. Here are some of the euphemisms used as substitutes for the adjective pregnant: in an interesting condition, in a delicate condition, in the family way, with a baby coming, (big) with child, expecting.
The apparently innocent word trousers, not so long ago, had a great number of euphemistic equivalents, some of them quite funny: unmentionables, inexpressibles, indescribables, unwhisperables, you-mustn't-men-tion 'ems, sit-upons. Nowadays, however, nobody seems to regard this word as "indecent" any more, and so its euphemistic substitutes are no longer in use.
Euphemisms may, of course, be used due to genuine concern not to hurt someone's feelings. For instance, a liar can be described as a person who does not always strictly tell the truth and a stupid man can be said to be not exactly brilliant.
All the euphemisms that have been described so far are used to avoid the so-called social taboos. Their use, as has already been said, is inspired by social convention.
Superstitious taboos gave rise to the use of other type of euphemisms. The reluctance to call things by their proper names is also typical of this type of euphemisms, but this time it is based on a deeply-rooted subconscious fear.
Superstitious taboos have their roots in the distant past of mankind when people believed that there was a supernatural link between a name and the object or creature it represented. Therefore, all the words denoting evil spirits, dangerous animals, or the powers of nature were taboo. If uttered, it was believed that unspeakable disasters would result not only for the speaker but also for those near him. That is why all creatures, objects and phenomena threatening danger were referred to in a round-about descriptive way. So, a dangerous animal might be described as the one-lurking-in-the-wood and a mortal disease as the black death.
The Christian religion also made certain words taboo. The proverb Speak of the devil and he will appear must have been used and taken quite literally when it was first used, and the fear of calling the devil by name was certainly inherited from ancient superstitious beliefs. So, the word devil became taboo, and a number of euphemisms were substitutes for it: the Prince of Darkness, the black one, the evil one, dickens (coll.), deuce (coll.), (Old) Nick (coll.).
The word God, due to other considerations, also had a great number of substitutes which can still be traced in such phrases as Good Lord!, By Heavens/, Good Heavens!, (My) goodness!, (My) goodness gracious!, Gracious me!
to die which has a long chain of both solemn and humorous substitutes. E. g. to pass away, to be taken, to breathe one's last, to depart this life, to close one's eyes, to yield (give) up the ghost, to go the way of all flesh, to go West (sl.), to kick off (sl.), to check out (sl.), to kick the bucket (sl.), to take a ride (sl.), to hop the twig (sl.), to join the majority (sl.).
