Sleeve
The kanji and the word are exactly the same. That means they share meanings as well.
そで
Since this word is made up of a single kanji, it probably uses the kun'yomi reading. You haven't learned this reading yet, so here's a mnemonic to help you:
You only wear sleeves because your soap is dead (そで). If it wasn't, you would go sleeveless forever! But, your soap is dead, so you have stinky armpits, which you hide in these sleeves.
ねえ、袖が汚れているよ。
Hey, your sleeve seems dirty.
このポロシャツ、袖が短すぎてノースリーブに間違われたんだよね。
This polo shirt's sleeves are so short that people mistakenly thought it had none.
先輩の袖から見えた腕の血管に見とれて車にひかれそうになったなんて誰にも言えない。
I can't tell anyone that I almost got hit by a car because I couldn't stop staring at the blood vessels that were showing on my senpai's arms from under his sleeves.