dropcloth

/ˈdrɑpˌklɔθ/
noun
  1. A large sheet of cloth, plastic, or other material used to protect floors, furniture, or surfaces from paint, dust, or debris during work.
    • Use a plastic dropcloth to protect the carpet from glue spills.
    • He spread a dropcloth on the floor before painting the ceiling.
    • The old dropcloth was covered in splatters from years of projects.