Teacher
noun, verbal noun
Who admonishes and teaches you? A Teacher. Probably not the nicest one though...
This word is more formal and specific than 先生 or 教師. It refers to licensed teachers who have permanent positions in schools, not temporary ones like supply teachers.
This is a jukugo word that uses the on'yomi readings of the kanji. You should be able to read this on your own.
あの教諭、昔の教え子と結婚したらしいよ。
Apparently that teacher married a former student they had a while ago.