0One of the best ways to improve or build up vocabulary is to write or use one-word substitutes for the given phrase. It is very important to write precisely and speak in a single word. Like the word autobiography can be used in place of the sentence, "The Life History Of a Man Written By Himself". This not only makes the language easily comprehensible but also makes it beautiful.
The other way, we can say that these words are used to bring an effect of compression in any kind of writing, for example in business communication there are instances when we have to write a lot within the limitation of time and space, there this kind of words can prove quite handy.
In the English language, there are a lot of words for a group of words that can be used effectively to make the writing to the point that too without losing the meaning of the context.
1. One who is recovering from illness = Convalescent
2. One who loves mankind = Philanthropist
3. One who copies from other writers = Plagiarism
4. One who hates women = Misogynist
5. One who knows many languages = Polyglot
6. One who is present everywhere = Omnipresent
7. One who works for free = Volunteer
8. A place where orphans live = Orphanage
9. A sentence whose sentence is not clear = Ambiguous
10. A study of animals = Zoology
