noun
General term for a teacher, instructor, or master in an educational or training context.
彼は高校の数学の先生です。
He is a high school math teacher.
ピアノの先生
I learned a new piece from my piano teacher.
noun, noun, used as a suffix
sensei; title of respect
Honorific title or form of address for teachers, doctors, lawyers, politicians, artists, and other respected professionals. Used both as a standalone noun and as a suffix attached to the person's name.
田中先生、質問があります。
Sensei Tanaka, I have a question.
弁護士の先生に相談した。
I consulted with my lawyer.
noun
(teasing) sir; (joking) master
Familiar or jocular form of address, often used teasingly among friends or when playfully deferring to someone. Not used in formal situations.
おや、先生、今日は一段とご機嫌ですね。
Well, well, sir, you're in an especially good mood today.
noun
one's elder
Archaic original meaning referring to an older person or one's elder. Not used in modern Japanese outside of historical contexts.
古典では「先生」が年長者を指すことがある。
In classical texts, 先生 can refer to an elder.