5. The method of claim 1 , wherein the verifying of the unregistered words and the determining of the semantic classes of the verified unregistered words comprise: generating a search word for the unregistered words and performing a search through a searching unit; extracting usage examples of the unregistered words from the search for the search word; verifying the unregistered words with the usage examples according to a predetermined unregistered word verification method; and determining the semantic classes of the unregistered words among candidate semantic classes of the unregistered words according to the usage examples.
5. The method of claim 1 , wherein the verifying of the unregistered words and the determining of the semantic classes of the verified unregistered words comprise: generating a search word for the unregistered words and performing a search through a searching unit; extracting usage examples of the unregistered words from the search for the search word; verifying the unregistered words with the usage examples according to a predetermined unregistered word verification method; and determining the semantic classes of the unregistered words among candidate semantic classes of the unregistered words according to the usage examples. 8. The method of claim 5 , wherein according to the unregistered word verification method, it is verified whether the unregistered word is expressed by any one of parentheses, quotation marks, brackets, a bold letter attribute, and an underline.