Many shapes have metaphorical names, i.e., their names are
metaphors: these
shapes are named after a most common object that has it. For example, "U-shape" is a shape that resembles the letter
U, a
bell-shaped curve has the shape of the vertical cross section of a
bell, etc. These terms may variously refer to objects, their
cross sections or
projections.
Types of shapes
Curves
The
Fish bladder is the intersection of two congruent disks, each centered on the perimeter of the other
Tomahawk curve, with its handle and spike thickened
Some of these names are "classical terms", i.e., words of
Latin or
Ancient Greeketymology. Others are
English language constructs (although the base words may have non-English etymology). In some disciplines, where shapes of subjects in question are a very important consideration, the shape naming may be quite elaborate, see, e.g.,
the taxonomy of shapes of
plantleaves in
botany.
Biconic shape, a shape in a way opposite to the hourglass: it is based on two oppositely oriented
cones or
truncated cones with their bases joined; the cones are not necessarily the same
Geoid (From Greek Ge (γη) for "
Earth"), the term specifically introduced to denote the approximation of the shape of the
Earth, which is approximately spherical,
but not exactly so
Heart shape, long been used for its varied symbolism
Hourglass shape or hourglass figure, the one that resembles an
hourglass; nearly symmetric shape wide at its ends and narrow in the middle; some flat shapes may be alternatively compared to the
figure eight or hourglass