2. Bare, stark, barren share the sense of lack or absence of something that might be expected. Bare, the least powerful in connotation of the three, means lack of expected or usual coverings, furnishings, or embellishments: bare floor, feet, head. Stark implies extreme severity or desolation and resultant bleakness or dreariness: a stark landscape; a stark, emotionless countenance. Barren carries a strong sense of sterility and oppressive dullness: barren fields; a barren relationship. 6. See mere¹.

Did you mean backrest?