noun, noun or participle which takes 'suru', intransitive verb
sleeping together; sharing a bed
Literary or formal term for sleeping in the same bed, often implying intimacy. In modern casual speech, 一緒に寝る is more common.
二人は同衾して一夜を過ごした。
The two spent the night sleeping together.
Casual, everyday expression for sleeping together or sharing a bed, without the literary or formal nuance of 同衾.
Compound of 同 (same) and 衾 (bedding, quilt). The exact historical derivation is uncertain, but the spelling is conventionally associated with the meaning of sharing a bed.