A term historically used to describe a state of mental fatigue or clouded thinking, often in a school setting.

मानसिक थकावट

English Usage: After studying for hours, I felt a brain fag that made it hard to concentrate.

Hindi Usage: घंटों पढ़ाई करने के बाद, मुझे मानसिक थकावट महसूस हुई जिससे ध्यान केंद्रित करना मुश्किल हो गया।