The meaning of "Design" by Robert Frost is that all things that men relate to within the universe have a certain type of evil within their innocence. The poem focuses around the way that all of humanity is necessarily cruel.
In the beginning of the poem, Frost details the way that a spider catches a moth. The moth is holding onto a flower because it knows that it is going to be eaten by the spider, but there is nothing that the moth can do because the spider is a fierce predator that is going after its meal. The beginning of the poem seems somewhat innocent in the way that nature is described, because it is a commonly accepted fact that spiders eat insects.
As the poem continues, it begins to take a darker turn. It is a clarification of what the narrator does and is a description of the way that the world can be a cruel place, although it is necessary for all things to survive. The poem is a traditional one with rhyming stanzas and theme work. It is true to the nature of Robert Frost because the majority of his poems take unconventional turns and often have underlying dark themes.