noun
middle reaches of a river; midstream; middle course
Used for the middle part of a river or stream, between 上流 and 下流; depending on context it can also refer to being in the middle of the current.
この川の中流には小さな町が点在している。
Small towns are scattered along the middle reaches of this river.
ボートは川の中流まで流
The boat was carried out into the middle of the stream.
noun
Refers to a middle social or economic stratum, as in 中流家庭 or 中流階級. It contrasts naturally with 上流 and 下流 in social-class contexts.
彼女は中流家庭で育った。
She grew up in a middle-class family.
多くの人が中流の暮らしを望んでいた。
Many people hoped for a middle-class life.