As they've recently released a new version of definition search (googlesystem.blogspot.com/2011 ...), the define: operator has stopped working on any Google versions (at least from France).
A search for [define:apple] now return:
> No definitions were found for apple.
> – Make sure all words are spelled correctly.
> – Search the Web for documents that contain "apple"
I don't get why they don't show the same SERP as [define apple], or even better, the results with the new "dictionnary filer" (available in the more search tools menu).
Same problem in South Africa over the past week