Google says there are 13,653,070 unique words in common use with Search Engines, after discarding words that appear less than 200 times. Examples of words that don't make the cut are the numerous different spellings of Britney Spears.
The Google data shows some of the misspellings detected by their spelling correction system for the query [ britney spears ], and the count of how many different users spelled her name that way. Each of these variations was entered by at least two different unique users within a three month period, and was corrected to [ britney spears ] by their spelling correction system (data for the correctly spelled query is shown for comparison). Everything from Brittany Spears (40134 errors) to all manner of other errors.
