Variety is the spice of language. The words listed in this book are not intended to replace those that most people use most of the time. Rather, they are variations on the theme. We tend to use the same old words over and over again, to limit our powers of expression by limiting our vocabulary. There is nothing wrong with the "old words", but why not enhance your speech and writing by learning to use new ones from time to time as alternatives? 
    How often have you spoke of having an accident? Why not use the alternative mishap (小事故. once in a while? Everyone talks of the usual thing to do or expect. Might not one, to enrich his speech, speak of the customary thing? Or why not occasionally describe a situation as aggravated instead of worsened? 
    Don't throw away the "old words". Vary them with the "new words". English is an especially rich language, and often there are delicate shades of difference between two words that are generally regarded as equivalent or synonymous. Thus, a mishap is not merely an accident; it is an unfortunate accident. (There can be fortunate accidents, like bumping into an old friend you haven't seen for years and whose address you've lost. . So, in using mishap instead of accident, you must be sure of the distinction. Again, you'd never say "as customary" rather than "as usual", because the latter phrase has become art of the language. But wouldn't it sometimes be pleasant and perhaps more interesting to describe a kind act by someone as having been done with his customary rather than his usual thoughtfulness? Other examples: fragrant, for smelling good, or having a nice smell; morsel, for bit; wayward, for disobedient; deft, for skillful or clever. 
    No doubt a good many words in the list will be familiar to you, but do you use them, or do they remain the  "property" of others? They are included to introduce variety, and, more often than not, subtle shades of meaning into your speech and writing. Try to make these words your own, as companions or friendly rivals of the ones you have managed with in the past. Let them compete, and make your language all the richer. 
    Many words have more than one meaning. In such cases, I have given the meaning or meanings most likely to be used in everyday speech, omitting the rest. As an example, the word docile means not only   "easily led" or "manageable", but also "easily taught" or "teachable". (Docile comes from the Latin docilis, whose first meaning is  "teachable", and is based on the Latin verb docere, meaning to teach, a form of which, doctus, meaning "taught", gave us our word doctor. . In this book, only the meaning "easy to manage or lead" is given, because the other use "teachable" is very rare in everyday English usage. Or take ghastly, which means "ghostlike" as well as "horrible, dreadful"  (as in a ghastly accident or a ghastly mistake.. The first meaning is sufficiently rare, for the purposes of this book, to warrant omission.