donkey jacket 
noun British
A heavy jacket which has a patch of waterproof leather or plastic across the shoulders, worn typically by building workers.He leapt forward and took off his donkey jacket and wrapped it round her shoulders....
- He has been missing from his address since last Monday, and was last seen wearing a donkey jacket and dark trousers, with a blue or black checked shirt.
- It tends to consist of three fleeces, a jumper and a donkey jacket - and that's just in the summer.