noun
Refers to a toilet or restroom, but in modern everyday Japanese it is especially common as the first part of compounds such as トイレットルーム and トイレットペーパー. The shorter トイレ is the more ordinary standalone word.
トイレットルームは二階にあります。
The restroom is on the second floor.
トイレットペーパーを買い忘れた。
I forgot to buy toilet paper.