A tarpaulin (US: /ˈtɑːrpəlɪn/, UK: /tɑːrˈpɔːlɪn/), or tarp, is a large sheet of strong, flexible, water-resistant or waterproof material, often cloth such as canvas or polyester coated with urethane, or made of plastics such as polyethylene. In some places such as Australia, and in military slang, a tarp may be known as a hootch. Tarpaulins often have reinforced grommets at the corners and along the sides to form attachment points for rope, allowing them to be tied down or suspended.
Inexpensive modern tarpaulins are made from woven polyethylene; this material is so associated with tarpaulins that it has become colloquially known in some quarters as polytarp.
The word tarpaulin originated as a compound of the words tar and palling, referring to a tarred canvas pall used to cover objects on ships. Sailors often tarred their own overclothes in the same manner as the sheets or palls. By association, sailors became known as Jack Tars.