拖堂

tuōtáng
  1. to drag out a lesson
  2. to insist on extending class after the bell

CEDICT

to have a lesson run overtime; to extend class time

Wiktionary

拖長課堂時間規定下課時間依然持續授課

維基詞典

Examples

拖堂情况对于学生们而言十分常见。

Having their classroom time extended is a very common occurrence for students.

Source: Tatoeba

Entry Composition