the curve of the upper lip - where it curves and then there is a slight
dip.
it is in the shape of a bow, and lips are the 'love'(cupid) of your
face.
hence the name "cupids bow"
some cupids bows dip loads more... and almost go down to the bottom of the top lip (where the lips
meet).
there are also lips that do not have a cupids bow, so they would just be rounded at the
top with no dip so it would be like a mirror image of the bottom lip.
person a: you have
really nice
lips
person b: thanks, yours are nice too
person a: well not
really, i dont have a cupids bow
person b: so...