博士
bó shì
doctor (as an academic degree)
(old) person specialized in a skill or trade; (old) court academician
broad (博) + scholar (士) = doctorate
博 suggests breadth and completeness — mastery across many domains. 士 was the old honorific for a learned, respected man of standing.
他刚拿到博士学位，全家都很高兴。
tā gāng ná dào bó shì xué wèi，quán jiā dōu hěn gāo xìng。
he just got his doctoral degree, and the whole family is very happy.
读博士需要花很多年做研究。
dú bó shì xū yào huā hěn duō nián zuò yán jiū。
pursuing a doctorate requires spending many years doing research.