sit-upon
noun
a piece of waterproof fabric or other material carried by campers, hikers, etc., and used for sitting on wet surfaces.
The grammatical form denoting more than one person, place, thing, or idea.
Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.
But I should advise you, old fellow, to get your sit-upons seated with wash-leather, - just like the eleventh hussars do with their cherry-coloured pants.
From Adventures of Mr. Verdant Green by Cuthbert Bede