The language has grown by more than 70 per cent since 1950 .... The previous half century it only grew by 10 per cent ... source
Are all these new words in the dictionary?
English does not have an equivalent version of the Académie française. The only official recognition comes with an entry in the Oxford English Dictionary (OED). Interestingly much of this new vocabulary has not been formally recognised.
Nearly half of the new words are not included in any dictionary and are dubbed lexical "dark matter". They are either slang or invented jargon.
Why does the OED restrict the words it includes?
Where are we going to put them all these new words? I asked myself, looking at the 20 volume, 650,000 word complete Oxford English Dictionary (OED) on the shelf behind me. Even the comically misnamed Shorter OED is two very fat volumes.In fact the OED has come up with a solution - it's gone exclusively online! That will save library shelf-space but are we losing something?
Concise Oxford English Dictionary: 11th Edition Revised 2008
Shorter Oxford English Dictionary: Sixth Edition
Oxford Advanced Learner's Dictionary