One feature Hoon lacks: a context that isn't a first-class value. Hoon has no concept of scope, environment, etc. An expression has exactly one data source, the subject, a noun like any other.
Limbs
A limb is used to resolve to a piece of data in the subject. A wing is thus a resolution path into the subject.
Wings
In Hoon we use 'wings' to extract information from the subject. A wing is a list of limbs (including a trivial list of one limb).