Bee’s knees

What is Bee’s knees?

Bee’s knees definition and meaning on Dictionary terms:
noun

any hymenopterous insect of the superfamily Apoidea, including social and solitary species of several families, as the bumblebees, honeybees, etc.
the common honeybee, Apis mellifera.
a community social gathering in order to perform some task, engage in a contest, etc.: a sewing bee; a spelling bee; a husking bee.