Translation guide
A raincoat is a waterproof coat worn to protect against rain. In Japanese, the most common word is レインコート, a loanword from English. There are also traditional terms like 雨合羽 and 雨具, but レインコート is the default in modern conversation.
レインコート
raincoat
A waterproof coat for rain, typically modern and Western-style.
The most common and neutral word for a raincoat. Used in everyday speech and writing.
雨が降りそうだから、レインコートを持って行こう。
It looks like rain, so let's take a raincoat.
A traditional Japanese raincoat, often made of oiled paper or plastic. Can sound old-fashioned or refer to a specific style.
A general term for rain gear, including raincoats, umbrellas, etc. Not specifically a raincoat.
In modern Japanese, レインコート is the standard word for a raincoat. 雨合羽 (あまがっぱ) is more traditional and may refer to a specific style, like a poncho or a coat made of oiled paper. Use レインコート unless you want to evoke a nostalgic or traditional feel.
祖父は昔、雨合羽を着て田んぼに行った。
My grandfather used to go to the rice fields wearing a raincoat.
Rain gear is essential for mountain climbing.