Leather Jacket
noun
革 is leather and ジャン is short for ジャンパー (Jumper, like a jacket). So, put those together and you have a leather jacket.
This word is getting somewhat outdated. The trendier term now is レザージャケット.
The reading is the same as the vocab word 革, because this word is like two separate words put together (so it's treated as single words too, giving it that reading).
古着屋さんでビンテージものの革ジャンを見つけた。
I found a vintage leather jacket at a second-hand clothing shop.
いや、あんな高い革ジャン買えるわけないじゃん。
No way, I can't afford such an expensive leather jacket like that.
雪が降ってきたので、ビエトは、コウイチに革ジャンを掛けてやった。
It started snowing, so Viet covered Koichi with his leather Jacket.