apian

As adjectives the difference between apian and avian

is that apian is relating to bees; beely while avian is characteristic of or pertaining to birds, or to bird-like or flying creatures.

As a noun avian is

a bird.

As a proper noun apian

is of a german noble family.

As a noun pian is

pain.

As a noun apiin

is a chemical compound isolated from parsley and celery, and whose aglycone is apigenin.

As an adjective apian is

relating to bees; beely.