sensei
noun [ C ] uk/senˈseɪ/ us/ˈsen.seɪ/
（空手道或其他武术）老师，先生
a teacher of karate or other martial art (= a traditional Japanese or Chinese form of fighting or defending yourself)
At a command given by the sensei, members of the class show their respect to the instructor by bowing. 老师一声令下，全体成员向教官鞠躬表示敬意。