This joins a small but distinguished group of words which are directly or ultimately borrowings into English from Hawaiian. It has been suggested that in some ways the OED itself resembles a wiki: its long tradition of working on collaborative principles means it has welcomed the contribution of information and quotation evidence from the public for over 150 years.
I’ve just had an email from the OED telling me that this word, and others, have made their way into the OED at last.
[Shortened < WikiWikiWeb, the name of the first website of this kind, used as a program name and in URLs.
The name of the website is < Hawaiian wikiwiki very quick, emphatic form of wiki quick.]
A type of web page designed so that its content can be edited by anyone who accesses it, using a simplified markup language.
Edit: see also previous thread.