Before I start the topic on "oxymora", I want to dispel some misconceptions.  First, there is no such word as "oxymorons".  The correct plural is a word that ain't used much any mora.  Second, not every paradoxical expression or contradiction in terms is an oxymoron.  An oxymoron is a particular kind of expression that is used intentionally, for rhetorical effect.  Moreover, the contradiction is only apparent, not real, as the combination of terms provides a novel expression of some concept, such as "cruel to be kind".

Using the proper definition of the word, such popular expressions as "athletic scholarship" and "military intelligence" are not true oxymora.  Rather, they are called oxymora to draw attention to the terms that are (in a sense unintended by the expressions' coiners) contradictory.  Such expressions are called "oxymora" to disparage the institutions they represent.

How funny is it to see a "Swift" truck stuck in traffic?

"True Facts" was a section of the National Lampoon magazine.

"Athletic Scholarship"

"Military Intelligence"

"I'm a deeply superficial person" -- Andy Warhol, pop artist.

A sports commentator promised there would be more "Golf Action" after the following messages. (I received some hate email from a golfer who didn't see the humor in this one, but that was a long time ago.  I'd like some more hate mail, if you have it in you!)

(Click for more oxymorons)

"I believe we are on an irreversible trend towards more freedom and democracy--but that could change," noted Dan Quayle while he was Vice President.

"Obviously" -- If it is obvious, then there is no need to describe it with a sentence that begins with this word.  Obviously!  (Unless your real intent is to belittle your reader or listener, of course.)  Oh, and while I'm on the subject, the use of "of course" is almost as bad.    For some fun, search this page for instances of the words "obvious" and "course" to spot the places where I insult you.  Wasn't that fun?  It goes without saying!

Reader Stephanie points out she uses "of course" not to belittle her readers, but to make sure they don't belittle her.  In order to write in a clear and orderly fashion, she lays some groundwork.  She states some premises, that will be used later in the story.  These premises are things that are pretty obvious, but need to be said to provide foundation.  A reader, coming across these things, might be taken aback by the trumpeting of facts that the reader himself is well aware of.  The reader might think, "that Stephanie is pretty full of herself", as if she thinks she's discovered the Holy Grail or something.  So Stephanie writes "of course" as a matter of modesty, to head off this potential misunderstanding on the part of her reader. To avoid both problems (i.e. both the need to save face by labeling the obvious statement as such, and the possibility of insulting the reader by labeling obvious statements as such), there are other forms that can be used.  I like "I think we can agree that..." or "As we know..."  The use of "we" in this context might come across as a bit royal, though.  And definitely informal.  (But I like an informal style, even if I'm writing about a very dry subject, like math.)  Another approach might be to honestly explain to the reader why you're saying some things: "This is a complex subject, so it's hard to know where to begin.  So this paper will begin by stating some things that we all take for granted.  These statements don't break any new ground, but it's important to put them down on paper as a foundation for the results that will follow..."  And then from then on, just go on stating obvious things without labeling them as such -- the reader has been warned!

"pit" (verb) is a self-antonym (or contronym, or Janus-faced word) because it has two opposite meanings.  It can mean "to make pits in" or "to remove pits from".  Another contronym is "cleave".

A "Natural" child can mean either Illegitimate or Legitimate, according to the Merriam-Webster dictionary.  Definition 3a(1) is "begotten as distinguished from adopted; also: LEGITIMATE". Definition 3b is "ILLEGITIMATE <a natural child>"