also: てつがくはかせ
noun
Doctor of Philosophy; PhD
Refers to the academic degree, not the person holding it. The reading てつがくはくし is standard; てつがくはかせ is an older or less common variant.
彼は東京大学で哲学博士の学位を取得した。
He earned a PhD from the University of Tokyo.
哲学博士の論文を提出する締め切りは来月です。
The deadline to submit the PhD dissertation is next month.
Compound of 哲学 (tetsugaku, 'philosophy') and 博士 (hakushi, 'doctorate'). The reading はかせ for 博士 is an older form, now largely replaced by はくし in modern Japanese.