The vocabulary does not remain the same, but changes constantly. New notions come into being, requiring new words to name them. On the other hand, some notions and things become outdated and the words that denote them drop out of the language. Sometimes a new name is introduced for a thing or notion that continues to exist, and the older name ceases to be used. The number of words in a language is therefore not constant.
New words and expressions, or neologisms, are created for new things irrespective of their scale of importance. They may be very important, e.g. People 's Republic, nuclear war, or quite insignificant and short-lived, e.g. pony-tail (a hair-do), jitterbag (one who loves to dance to jazz-music), jitter (conversion) - a nervous man. Whenever a neologism appears
1. either an old word is appropriately changed in meaning, or
2. new words are borrowed, or
3. more other words are coined out of the existing language material ac
cording to the patterns and ways productive in the language at a given stage of
its development.
Thus, a neologism is any word or word-equivalent formed according to the productive structural patterns or borrowed from another language and felt by the speakers as something new.
The intense development of science and industry introduced an immense number of new words and changed the meanings of old ones: computer, nuclear fission - ðàñùåïëåíèå, feedback - îáðàòíàÿ ñâÿçü (ðàäèî), penicillin, tape-recorder, supermarket, sputnik, lunokhod, cosmic-ship, cosmodrome, etc.
There are many problems concerning neologisms: first of all the term «neologism» itself. The dictionary gives the explanation of a neologism as a new word or a new meaning of some word existing in the language. Hence there appear the problems: during what period of time is this new word or the new meaning of the word considered to be a neologism? Are the words, e.g. docking, cosmic flight, etc. registered in the dictionary neologisms or already not neologisms? Some scientists consider new words, which are already registered by the dictionaries, not to be neologisms. Then a new question arises: does it mean that neologisms are the words of oral speech?