A、Guess its meaning. B、Ask somebody. C、Refer to a dictionary. D、Add it to your word list. A

The average person learns most of the 30,000-40,000 words whose meanings we recognize by hearing them or getting familiar with them in the context without conscious effort.  [26] The best way to build a good vocabulary, therefore, is to read a great deal and to participate in a lot of good conversations. There are relatively few words that we learn permanently by purposefully referring to dictionaries or keeping word lists. Here are some suggestions of how to do it.
    Read plenty of good books. [27] When you come across a new word or a new meaning of an old word, stop and see if you can understand it from its context. If you can’t, and if you can manage without interrupting the thought of the book too much, look it up in a dictionary or ask somebody and then repeat its meaning to yourself a couple of times. If you are really conscientious, write the word and its meaning in a personal vocabulary list. Go over the list from time to time. Further, try to use the new word in writing or conversation a few times over the next several days.
    [28] Listen to good conversations and be alert to new words you hear or to new meanings of words you have already known. Then treat them just as you treat the new words you read.
    Learn and be alert to the parts of words: prefixes, suffixes and roots. Knowing them enables you to make intelligent guesses about the meanings of words.