in class

nod off

dozing off, nodding off / dying suddenly and without warning / nodding

to sleep / (figuratively) to die; to be buried

traditional folk song of Amami / (more broadly) traditional folk song of Okinawa

To do something completely (unintentionally); cannot help doing

indicates that something undesirable was done or happened

to close / to finish, do something completely / to put away, to put an end to / is, or was (with conjugation), done completely / happens, or happened, unexpectedly / is done with difficulty

teach; to instruct; give a lesson

instruction; teaching; school; lesson, class