Degree for many a prof

PHD

It’s the highest academic title earned after years of research and a dissertation defense.

This clue plays on the common abbreviation for a doctoral degree. "Prof" is short for professor, and many professors hold a PhD, which stands for Doctor of Philosophy. The word "degree" hints at an academic title, and "PHD" fits as the standard three-letter answer. It’s a straightforward definition with no hidden wordplay—just a nod to academic culture.