noun
Refers to the room itself, often used with の to modify a noun or in statements about being in the same room.
彼とは同室で働いている。
I work in the same room as him.
noun, noun or participle which takes 'suru', noun which may take the genitive case particle 'no', intransitive verb
sharing a room; occupying the same room
Focuses on the act or state of sharing a room, often used as a suru-verb or with する to mean 'to share a room'.
研修中は同室する予定だ。
We are scheduled to share a room during the training.
同室の人とすぐに仲良くなった。
I quickly became friends with the person I share a room with.