#concave_shape__concaveshape__concavity  a shape that curves inward
  supertype:  solid.shape  a three-dimensional shape
  subtype:  fossa__pit  a concavity in a surface (especially an anatomical depression)
     subtype:  glenoid_cavity__glenoidcavity__glenoid_fossa__glenoidfossa  the concavity in the head of the scapula that receives the head of the humerus to form the shoulder joint
     subtype:  glenoid_fossa__glenoidfossa__mandibular_fossa  a deep concavity in the temporal bone at the root of the zygomatic arch that receives the condyle of the mandible
     subtype:  pit_of_the_stomach__epigastric_fossa  a slight depression in the midline just below the sternum (where a blow can affect the solar plexus)
  subtype:  recess.concave_shape__reces__recession__niche__corner  a small concavity
     subtype:  pharyngeal_recess  a small recess in the wall of the pharynx
  subtype:  bowl.concave_shape__trough  a concave shape with an open top
  subtype:  scoop.concave_shape__pocket  a hollow concave shape made by removing something
  subtype:  depression.concave_shape__impression__imprint  a concavity in a surface produced by pressing; "he left the impression of his fingers in the soft mud"
     subtype:  dimple  a small natural hollow in the cheek or chin; "His dimple appeared whenever he smiled"
     subtype:  groove__channel  a long narrow furrow cut either by a natural process (such as erosion) or by a tool (as e.g. a groove in a phonograph record)
        subtype:  dado  a rectangular groove cut into a board so that another piece can fit into it
        subtype:  flute  a groove or furrow in cloth etc especially the shallow concave groove on the shaft of a column
        subtype:  quirk  a narrow groove beside a beading
        subtype:  rabbet__rebate  a rectangular groove made to hold two pieces together
        subtype:  track.groove  a groove on a phonograph recording
        subtype:  rut  a groove or furrow (especially one in soft earth caused by wheels)
        subtype:  stria__striation  any of a number of tiny parallel grooves such as: the scratches left by a glacier on rocks or the streaks or ridges in muscle tissue
     subtype:  dimple.depression  any slight depression in a surface; "there are approximately 336 dimples on a golf ball"
     subtype:  dip.depression  a depression in an otherwise level surface; "there was a dip in the road"
     subtype:  incision__scratch__slit__dent  a depression scratched or carved into a surface
        subtype:  scotch__score  a slight surface cut (especially a notch that is made to keep a tally)
     subtype:  sag__droop  a shape that sags; "there was a sag in the chair seat"
     subtype:  wrinkle__furrow__crease__crinkle__seam__line  a slight depression in the smoothness of a surface; "his face has many lines"; "ironing gets rid of most wrinkles"
        subtype:  crow's_foot__crow's_feet__laugh_line__laughline  a wrinkle at the outer corner of your eyes
        subtype:  dermatoglyphic  the lines that form patterns on the skin (especially on the fingertips and the palms of the hands and the soles of the feet)
        subtype:  line_of_life__life_line__lifeline  a crease on the palm; its length is said by palmists to indicate how long you will live
        subtype:  line_of_heart__heart_line__heartline__love_line__mensal_line  a crease on the palm; palmists say it indicates your emotional nature
        subtype:  line_of_fate__line_of_destiny__line_of_Saturn  a crease on the palm; palmists say it indicates how successful you will be
     subtype:  crevice__cranny__crack__fissure__chap  a long narrow depression in a surface
  subtype:  cup.concave_shape  any cup-shaped concavity; "bees filled the waxen cups with honey"; "he wore a jock strap with a metal cup"; "the cup of her bra"
  subtype:  indentation.concave_shape  a concave shape in a surface or edge or coastline etc.
     subtype:  notch.indentation  a V-shaped or U-shaped indentation carved or scratched into a surface; "there were four notches in the handle of his revolver"
        subtype:  serration  a single notch in a row of notches; "one of the serrations was broken off"
           subtype:  sawtooth  a serration on a saw blade
        subtype:  thumb_index__thumbindex  one of a series of rounded notches in the fore edge of a book to indicate sections
     subtype:  notch  a V-shaped indentation; "mandibular notch"
        subtype:  incisure__incisura  (anatomy) a notch or small hollow
           subtype:  mandibular_notch  small indentation in the middle of the lower jawbone
     subtype:  cleft  a split or indentation in something (as the palate or chin)

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