Answer:
It means someone wants to get a degree in a field of study that allows them to compare languages to each other (Hence the comparative...) Philology is the study of language. I've heard a rumor that there's a college (Yes, ONE) in the US that offers this degree, but I haven't found it. The only college I know of for sure in the world that offers the degree is Oxford.
The idea is that older languages have influences on more recent ones, and that some languages are 'related' so to speak.