noun
testing room; laboratory
A room used for conducting tests, experiments, or examinations. Can refer to a scientific lab or a room where exams are held.
学生たちは試験室に入って、静かに席に着いた。
The students entered the testing room and quietly took their seats.
新しい薬の効果を試験室で調べている。
They are investigating the effects of the new drug in the laboratory.
研究室 is a research room or a professor's office/lab, often used for academic research, whereas 試験室 is more about conducting tests or exams.
Compound of 試験 (test, experiment) and 室 (room). The exact historical derivation is uncertain, but the meaning is transparent from its components.