Afternoon Sun
Setting Sun, Evening Sun
noun
The west sun is, of course, the afternoon sun.
西日 describes the sun when it's in the western part of the sky. It generally refers to the afternoon sun, but it can also mean the setting sun or the evening sun. Basically, you can use it for sun or sunlight from mid-afternoon until sunset!
This word uses kun'yomi readings for both 西 (にし) and 日 (ひ). You've seen these readings before, so if you can remember that they're kun'yomi then you're good to go! Just watch out for that rendaku that changes ひ to び.
西日が当たる
the afternoon sun shines on
西日がさしこむ
the afternoon sun streams in
西日がさす
the afternoon sun shines
西日が入る
the afternoon sun enters
西日がまぶしくて、テレビが見えません。
The afternoon sun is so bright I can't see the TV.
西日でカーテンがオレンジ色に光りました。
The setting sun made the curtains glow orange.
西日が強くて、サンルームがサウナみたいになっています。
The afternoon sun is so strong that the sunroom is like a sauna.