groundsheet
noun
ground·sheet ˈgrau̇n(d)-ˌshēt 
: ground cloth
Example Sentences
Recent Examples on the Web Car campers may pay, but hikers just spread out a groundsheet and a sleeping bag, and the spot is theirs; only a bear can pull rank. 
Nicholas Kristof, National Geographic, 8 Sep. 2020
Nicholas Kristof, National Geographic, 8 Sep. 2020 Word History
First Known Use
1907, in the meaning defined above