1Entering a room (e.g., a classroom or other enclosed space). Often used in notices like 'No entry'.
試験中は入室を許可しない場合があるので注意してください。
Be aware that entry to the room may not be permitted during exams.
会場の入口に『関係者以外入室禁止』と書かれていた。
A sign at the venue entrance read 'No entry except authorized personnel.'
彼は授業開始の直前に入室した。
He entered the classroom just before the lesson started.
2In Buddhism, entering a teacher's tutelage; formally becoming a pupil of a Buddhist master.
若い僧が有名な師に入室して修行を始めた。
A young monk entered the tutelage of a famous master and began training.
伝統的に入室は正式な儀礼を伴うことが多い。
Traditionally, entering a teacher's tutelage often involves formal rituals.