#gatepost  either of two posts that bound a gate
  supertype:  post.upright  upright consisting of a piece of timber or metal fixed firmly in an upright position
  subtype:  hinging_post__hingingpost__swingingpost  the gatepost on which the gate is hung
  subtype:  shutting_post  the gatepost against which the gate closes

No statement uses or specializes gatepost; click here to add one.