upholster
Upholster (verb) means to cover furniture with soft padding and fabric.
Etymology
A back-formation from upholsterer (“tradesman who finishes furniture”), which comes from Middle English upholdester, a variant of Middle English upholder (“dealer in small goods”), from upholden (“to repair, uphold”); equivalent to uphold + -ster. Its sense development and form may also have been shaped by conflation with the unrelated word bolster.