seatback

seat +‎ back

seatback (plural seatbacks)

1. The usually vertical portion of a chair or similar piece of furniture that supports the back.
   • 1968 December, Popular Mechanics, volume 130, number 6, page 20:

     The Institute adds that seatback width can be reduced considerably to improve visibility without sacrificing support strength and antiwhiplash protection.

   • 2009 January 1, Stephen Milioti, “The Hand Points the Way”, in New York Times:

     The collection, called Kinesis, features a chair with a sensuous seatback and arms; the sleek lines look as if they would be at home in a Porsche.

2. A loose ornamental covering for the back of a sofa or chair.

• seat back

• back east, back seat, back-seat, backseat, set aback