1A natural watercourse — a river or stream. Everyday word covering anything from a small brook to a large river. Sometimes written 河, but 川 is the standard form in modern Japanese.
夏休みに子どもたちと近くの川で泳いだ。
I went swimming with the kids in a nearby river over summer vacation.
大雨で川の水位が一気に上がった。
The heavy rain caused the river's water level to rise sharply.
この辺りの川にはまだ鮎がいるらしい。
Apparently there are still sweetfish in the rivers around here.
川沿いの道を自転車で走るのが気持ちいい。
It feels great to cycle along the road by the river.
2A suffix attached to river names, usually voiced as -gawa via rendaku (e.g., Tama-gawa, Sumida-gawa, Shinano-gawa). Used as part of place names and proper nouns.
信濃川は日本で一番長い川です。
The Shinano River is the longest river in Japan.
多摩川は東京と神奈川の境を流れている。
The Tama River flows along the border between Tokyo and Kanagawa.