Source : Webster's Revised Unabridged Dictionary (1913)

Hyphae \Hy"ph[ae]\, n. pl. [NL., fr. Gr. "yfh` a web.] (Bot.)
   The long, branching filaments of which the mycelium (and the
   greater part of the plant) of a fungus is formed. They are
   also found enveloping the gonidia of lichens, making up a
   large part of their structure.

Source : WordNet®

hypha
     n : any of the threadlike filaments forming the mycelium of a
         fungus
     [also: {hyphae} (pl)]

hyphae
     See {hypha}