Noun
きょうしつ
学生は、教室ではじめに何をしますか。
What will the students do in the classroom first?
かれは教室でタバコをくわえたところを、先生に目げきされました。
The teacher witnessed him putting a cigarette in his mouth in the classroom.
先生がいなくなったのはたったの五分間だけだったが、大学生たちは完璧に教室を滅茶苦茶にしてしまった。
The teacher had only been gone for five minutes, but the university students had completely trashed the classroom.
The teaching room is just a classroom.
This is a jukugo word, which usually means on'yomi readings from the kanji. If you know the readings of your kanji you'll know how to read this as well.