carpet slipper 
noun British
A soft slipper whose upper part is made of wool or thick cloth.The next day his father Carlton, who was in the Merchant Navy, went to work in carpet slippers, the only footwear not destroyed....
- One of the new lads, bless his heart, eschewed the military regulation black, highly polished boots, and habitually turned up for parade in his carpet slippers.
- I picked up a new pair of trainers, some carpet slippers (the kitchen tiles are COLD in the morning) and a new winter jacket.