backside

/ˈbæksaɪd/
noun
  1. The part of the body that you sit on; the buttocks.
    • She slipped off the chair and bruised her backside.
    • The toddler landed right on his backside with a surprised look.
    • He fell on his backside on the icy sidewalk.
  2. The rear or reverse side of something, such as a building, object, or piece of paper.
    • The backside of the house faces a quiet garden.
    • Please write your name on the backside of the form.
    • The backside of the mountain is much steeper than the front.
Antonyms
What does "backside" mean? | whatsthatwordmean | whatsthatwordmean