schoolroom
/ˈskuːlrʊm/noun
1- a room used for lessons, especially the main classroom in a small school课堂, 教室（尤指小学校的主要教室）。
1.1
the schoolroom
used to refer to school as an institution学校：I was green as grass, straight out of the schoolroom.
我当时刚出校门, 还很幼稚。