It ain’t just a river in Egypt! Crossword Clue

 The answer to the crossword clue "It ain’t just a river in Egypt!" is PUN.

The clue is a play on words, with "denial" also meaning "the Nile" (river). Making this statement to someone is a roundabout but witty way to indicate that they are in denial about something in their life. The idea is that if the Nile (denial) were only a river in Egypt, it would be easy to see and acknowledge. However, since denial is not just a river in Egypt, it is more difficult to see and acknowledge.

The word "pun" is a play on words, and in this case, the play on words is between the two meanings of the word "denial."

I hope this helps!