also: りがくはくし
noun
Doctor of Science; DSc
An academic degree in the sciences, equivalent to a PhD in science. The reading りがくはかせ is more common than りがくはくし.
彼は東京大学で理学博士の学位を取得した。
He earned a Doctor of Science degree from the University of Tokyo.
理学博士の称号を持つ研究者が講演を行った。
A researcher with the title of Doctor of Science gave a lecture.
Compound of 理学 (rigaku, 'science') and 博士 (hakase/hakushi, 'doctor'). The term follows the pattern of academic degree names in Japanese.