“edge” is one of the last poems plath wrote before her suicide. how does knowing this information affect your understanding of the poem?

You start to see in it presentiments of her suicide. The name proposes being on the edge or having slipped off it. Since the poem is about a "perfected woman," one begins to read it as the poem about Plath herself dead, perfect. You can see how unhappy that she feels when turning over this message and you can almost see what she is planning to do.  It makes you more conscious of others who may be in need of help when you least comprehend it.

voracity is the noun corresponding to the adjective voracious, which means (1) eager to consume a great amount of food, or (2) marked by an insatiable appetite. veracity is far more common than the rare voracity, so the latter is sometimes used in place of the former.