"Applications must not contain any obscene, pornographic, offensive or defamatory content or materials of any kind (text, graphics, images, photographs, etc.), or other content or materials that in Apple's reasonable judgement may be found objectionable by iPhone or iPod touch users."
The screenshot provided with the rejection notice should the same type of words as in the OP. Again, words you had to search for to find.
More recently, Apple decided that because Dictionary provides uncensored access to Wikipedia, it must carry a 17+ rating. The text in this case was:
"Dictionary allows unfiltered access to Wikipedia, which includes frequent mature or suggestive themes. Applications must be rated accordingly for the highest level of content that the user is able to access."
As an app developer, this kind of behavior on Apple's part is very frustrating. Apple have fallen off their rocker, IMO.