Philology is the study of words, especially the history and development of the words in a particular language or group of languages. --Collin Dictionary
Phiology is a branch of linguistics, to which relevant scholars devote themselves in their disciples respectively on the basis of their serious researches, rather than pull an imaginary rabbit out of someone's the hat and present to other people with their own coined explanations.
Chinese professor Ju Xianlin who was very rigorous in his research of Tocharian language, etc. along with his German tutors. For ten years, they took very slow baby footsteps in this language which is extinct.