expression, ichidan verb
have sex; have a physical relationship
Euphemistic expression for having sexual intercourse; literally 'to pile bodies on top of each other'. Used in romantic or literary contexts to soften the directness.
二人は付き合って半年で体を重ねた。
They had sex after dating for half a year.
彼女は結婚するまで体を重ねたくなかった。
She didn't want to have a physical relationship until marriage.