Statement

When William encounters a new English word, he usually looks for its definition in the dictionary. For example, a definition for the word "unencumbered" is as follows: Sometimes this process creates a recursion, because William might then need to look up the definition for "burden", which again might be using new words that William doesn't know yet. To avoid encountering this issue, you should know that every dictionary has a defining vocabulary: a fixed list of words that was used to write the dictionary's definitions. For example, the Longman Dictionary of Contemporary English uses a defining vocabulary of approximately 2000 words, while the Oxford Advanced Learner's Dictionary uses one of approximately 3000 words. If you learn all of those beforehand then you can safely read the dictionary without encountering unexpected words. Learning a couple thousand words just to be able to use a dictionary is too much to ask of William: being lazy, he always looks for an easier way...