#hole.opening  an opening into or through something
  supertype:  opening.space__gap  an open or empty space in or between things; "there was a small opening between the trees"; "the explosion made a gap in the wall"
  subtype:  aperture.hole  an opening in something
     subtype:  pupil  contractile aperture in the iris of the eye
     subtype:  micropyle  minute opening in the wall of an ovule through which the pollen tube enters
     subtype:  stoma.aperture__pore  a minute epidermal pore in a leaf or stem
  subtype:  bolt-hole  a hole through which an animal may bolt when pursued into its burrow or den
  subtype:  bullet_hole  a hole made by a bullet passing through it
  subtype:  cranny  a small opening or crevice (especially in a rock face or wall)
  subtype:  leak.hole  an accidental hole that allows something (fluid or light etc.) to enter or escape; "one of the tires developed a leak"
  subtype:  ozone_hole__ozonehole  an area of the ozone layer (near the poles) that is seasonally depleted of ozone
  subtype:  perforation.hole  a hole made in something; "a perforation of the eardrum"
  subtype:  rathole  a hole (as in the wall of a building) made by rats
  subtype:  knothole  a hole in a board where a knot came out

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