An antimacassar is a small cloth placed over the backs or arms of chairs, or the head or cushions of a sofa, to prevent soiling of the permanent fabric.
Macassar oil was a very popular grooming product for men in the early 19th century (much like Jheri Curl in the 1970's and '80's) but was not popular among housewives who had to deal with the resulting soiled seat backs and arm covers. To combat the problem, doilies and fabric covers were fashioned to protect the permanent upholstery from permanent damage.
Antimacassars are still used today on upholstered furniture and commercial vehicles such as plane and train seats.
And there's your word of the day!