This dictionary is not based on the Oxford English Dictionary and should not be mistaken for a new or updated version of the OED.
It is a completely new dictionary which strives to represent as faithfully as possible the current usage of English words. The editor, Judy Pearsall, claims it is based on modern understanding of language. Some unorthodox choices made by the editors made this dictionary controversial amongst lexicographers.
It was first published in 1998.
See also: New Oxford American Dictionary