bootee

noun3

1. •
   A soft, woolen shoe, usually knitted, for a baby or small pet.

   • Take off the baby's bootees before you put her in the crib.
2. •
   An overshoe or sock worn to cover dirty shoes or feet.

   • Surgeons often slip on bootees before entering the operating room.
3. •
   A thick sock worn under a wetsuit.