What is the meaning of Hazel?

A shrub or small tree of the genus Corylus, as the C. avellana, bearing a nut containing a kernel of a mild, farinaceous taste; the filbert. The American species are C. Americana, which produces the common hazelnut, and C. rostrata. See Filbert.

Source: Webster’s Revised Unabridged Dictionary (1913), via OPTED