LONDON — It weighs in at more than 130 pounds, but the authoritative guide to the English language, the Oxford English Dictionary, may eventually slim down to nothing the 126-year-old dictionary's next edition will be printed on paper at all. The digital version of the Oxford English Dictionary now gets 2 million hits a month from subscribers, and dozens of free online dictionaries offer word meanings at the click of a mouse. Dictionary.com even offers a free iPhone application.