An oxymoron is usually defined as a phrase in which two words of contradictory meaning are brought together:-

1) Clearly misunderstood

2) Exact Estimate

3) Small Crowd

4) Act Naturally

5) Found Missing

6) Fully Empty

7) Pretty ugly

8) Seriously funny

9) Only choice

10) Original copies

And the best of all......

11) Happily Married