Japanese word corresponding to "teacher" in English. Literally translates to "one who has gone before". In addition to being a noun, it is also an honorific suffix used with a teacher's name (never one's own name).

Hashimoto-sensei wa Nihon-jin desu ne.
Mr. Hashimoto is Japanese, isn't he?

Written sen-sei with the kanji for "before; ahead" and "life; birth".