Although a true oxymoron is “something that is surprisingly true, a paradox”, modern usage has brought a common misunderstanding as being near synonymous with a contradiction.
An oxymoron is a figure of speech that combines normally contradictory terms. They appear in a range of contexts, from inadvertent errors such as extremely average, to deliberate puns like same difference, to literary oxymorons that have been carefully crafted to reveal a paradox.
And I have a really great agent and I know it's almost an oxymoron to say you have a smart agent. But she is and she has a beautiful aesthetic and she has guided me. Patricia Clarkson