• 教師きょうし — teacher
• 医師いし — doctor (medical)
• 技師ぎし — engineer
• 師団しだん — division (military)
• 師匠ししょう — master (in art or craft)
• 僧師そうし — monk-teacher

師 combines elements meaning “command” and “cloth,” originally referring to a group led by someone in authority — such as a military leader. Over time, it took on the meaning of “teacher” or “master” — someone who leads others in skill or knowledge.

彼かれは 有名ゆうめいな 医師いしです。
He is a well-known doctor.

師匠ししょうから 多おおくを 学まなびました。
I learned a lot from my master.