4. The method of claim 1 , additionally comprising the steps of: translating, by a second machine translation module associated with the second language of the speech translation system, the corresponding translated word from the second language back into the new word of the first language, correlating the new word in the first language with the corresponding translated word of the second language and adding the corresponding translated word and its word class information to a second recognition lexicon of the second language; and updating the second machine translation module with the corresponding translated word and the word class information, wherein the second machine translation module contains a second tagging module, a second translation model and a second language module.
4. The method of claim 1 , additionally comprising the steps of: translating, by a second machine translation module associated with the second language of the speech translation system, the corresponding translated word from the second language back into the new word of the first language, correlating the new word in the first language with the corresponding translated word of the second language and adding the corresponding translated word and its word class information to a second recognition lexicon of the second language; and updating the second machine translation module with the corresponding translated word and the word class information, wherein the second machine translation module contains a second tagging module, a second translation model and a second language module. 6. The method of claim 4 , comprising the further step of inputting the new word into a text-to-speech pronunciation lexicon associated with the first language.