noun
sleeper; sleeping person
General term for a person who is sleeping, often used in contexts like identifying someone asleep on a train or in a shared space.
終電でスリーパーをよく見かける。
I often see sleepers on the last train.
noun
wearable blanket
Refers to a blanket-like garment that can be worn, popularized as a cozy loungewear item.
In winter, I like to spend time on the sofa wearing a wearable blanket.
noun
sleeper agent
Espionage term for an agent who remains dormant in a target country until activated.
そのスパイは長年スリーパーとして潜伏していた。
The spy had been undercover as a sleeper agent for many years.
noun
In bowling, a pin hidden behind another pin, making it difficult to see and knock down.
ボウリングでスリーパーを倒すのは難しい。
It's difficult to knock down a sleeper in bowling.