「雨」 (ame) means "rain." It is water that falls from the sky in drops. When you say "雨が降ります" (ame ga furimasu), it means "it rains." It's a common weather phenomenon that affects daily life.

「雨(あめ)」は、空(そら)から水滴(すいてき)が落(お)ちてくる自然現象(しぜんげんしょう)です。